Both of these sides head into this encounter as joint leaders of Group H following victories on the opening day of the competition last month. United saw off Turkish outfit Galatasaray 1-0, while Cluj won 2-0 away at Braga.
It would be fair to say that very little is known of Cluj, who are three-time winners of their domestic league.
Nevertheless, United boss Sir Alex Ferguson has insisted that his side will be taking their opponents seriously.
Stay tuned to find out if United can win through in North-West Romania.
9.37pmThat's just about all we have time from Cluj. I hope you've enjoyed the coverage. Be sure to check out our match analysis, which will be coming your way shortly.
9.36pmWell it wasn't pretty at times but United got the job done. However, it could have been so much different but for a smart save from De Gea deep into stoppage time. While the performance was patchy, Ferguson will only be concerned by the three points.
86 minBOOKING! First caution of night goes to Ferdinand for a high challenge on Bastos just inside the United half. The defender can have no complaints there.
85 minWe're getting to that stage now were a goal for Cluj would leave United little time to find a third. With that in mind, they've started to keep the ball more rather than exerting themselves to add to their tally.
82 minSUBSTITUTION: It's raining subs at the moment! Hernandez is replaced by Danny Welbeck.
80 minSUBSTITUTION: Final switch for Cluj sees Nicora come on in place of Aguirregaray.
79 minSUBSTITUTION: And that's it for Evans, the thigh injury has got the better of him. All of which means Wootton makes his European debut.
77 minCluj have offered very little in the way of an attacking threat for quite a while now. That's not to say they are out of this yet, but United do look in control.
74 minPENALTY APPEAL! Another shout from United falls on deaf ears. Van Persie cuts the ball back for Evra, who tumbles to the floor following a challenge from two defenders. Nothing doing as far as the referee was concerned.
71 minCHANCE! A hat-trick opportunity for Van Persie goes begging, just. Rooney beats his man on the left and drills in a cross. Van Persie's reaction is a split second too late and the danger is cleared. Any touch from the frontman would have turned the ball in.
66 minUnited defender Jonny Evans appears to be struggling with a thigh problem. The Northern Ireland international originally picked up the problem against Tottenham Hotspur on Saturday. If he can't continue, then young Scott Wootton may be handed his European debut.
61 minSUBSTITUTION: Goalscorer Kapetanos is given a breather, Bjelanovic comes on in his place.
60 minStill United control this match. They're stringing together a number of passes. If they can find a third goal soon, it should end this match as a contest. They'll have to be wary of Cluj on the break though. They've had a couple of chances since falling behind.
55 minSAVE! Another attempt on goal for the hosts. Captain Cadu finds himself with time and space inside the area. He heads goalwards, but De Gea in the United goal reacts quickly to turn the ball over.
52 minCHANCE! A sign of intent from the hosts. Kapetanos shows good movement to wriggle free inside the area but his shot flies over the bar. A warning sign for United nevertheless.
50 minWell that didn't take long! Rooney is again the creator, crossing for Van Persie who beats the Cluj goalkeeper to the ball and flicks the ball into an unguarded net. Smart finish from the Dutch international. Will Cluj now come out and attack a bit more? They've got to really.
47 minUnited start the second half pretty much in the same way they played throughout the first 45 minutes - on top. Can they find the all important second goal? Not if Anderson keeps shooting like that! The midfielder fires high, wide and not very handsome from the edge of the box.
8.45pm"We're doing most things correct. Losing the goal the way we did is a shocker, but we recovered from it," Ferguson tells ITV Sport at the break.
8.36pmWhile you wait for the second half, why not give our half-time report from Romania a read? Go on, you know you want to!
8.33pmSame old story as far as United are concerned. They've conceded in the opening 20 minutes for the fourth time this season. The equaliser was coming and they deserve to be level. However, they're having trouble creating clear cut chances. Introducing either Kagawa or Nani after the break could help carve open the Cluj defence on a more regular basis.
45 min...But his effort bounces comfortably into the hands of Felgueiras. Not his best effort, that's for sure.
44 minFree-kick to United 30 yards from goal as Bastos trips up Van Persie. Rooney looks like he wants to hit this...
42 minPENALTY APPEAL! Cleverley goes down in the area under a challenge from Aguirregaray. Minimal contact in my opinion - a view shared by the match official. Play on.
37 minUnited continue to dominate proceedings. Cluj really are playing some negative stuff at the moment. In fairness though if they came out and attacked, they would probably get well beaten. It's down to United to break them down.
34 minCHANCE! Van Persie almost doubles up when slipped in by Hernandez, but his drilled shot is cleared by the body of Felgueiras.
29 minBut then what do I know?! I've just United don't look like scoring and Van Persie levels! Rooney whips in a free-kick from the left which the unmarked Dutch striker somehow loops into the net. It wasn't the cleanest of connections, but they all count.
27 minThe match has gone back to how it was before the goal. United in complete control but they do not really look like breaking Cluj's stubborn resistance.
24 minSUBSTITUTION: Early injury-forced change for Cluj as Sougou goes off to be replaced by Luis Alberto.
21 minCHANCE! United should be back level. Cleverley dinks over a ball for Van Persie inside the area but the Dutchman swings his foot early and shoots wide.
19 minCHANCE! Rooney's been lively so far and he forces Felgueiras into action with a low drive on the edge of the box.
17 minStill a little shocked by that goal. Granted United hadn't look like scoring themselves, but they had dominated possession. Once again they have been the makers of their own downfall.
15 minI said Kapetanos would be the Cluj danger man and so it has proved. Sougou beats Evra far too easy down the right and his low cross his instantly turned past De Gea by the frontman. Poor defending from United - how many times has that been said this season?
10 minCHANCE! Rooney threads a pass through to Anderson on the edge of the box. The Brazilian insists on using his left foot when the right would have been easier and he shoots wide.
9 minStill all United. Cluj are camped on the edge of their area and are making it difficult for United to pass. Could be in for a long night if this continues.
6 minUnited are seeing a lot of the ball at the moment and Cluj seem happy to let them have it. The home side are defending narrowly and as a unit.
3 minCHANCE! And that is almost 1-0 to the home side. Sougou meets the corner and his glancing header just misses the upright. Ferguson has bemoaned his side's poor starts this season and they almost had another one.
2 minCorner to Cluj as Ferdinand blocks a low cross...
2 minEarly link up between Rooney and Hernandez ends with the England international over-hitting a pass for his teammate. Promising signs nevertheless.
7.41pmHere come the players to a loud reception from the crowd inside the Dr. Constantin Radulescu (great name) Stadium. Anthem and handshakes to come and then we'll be off and running.
7.40pmRight, the players are in the tunnel. Patrice Evra will captain United today by the way.
7.39pm"Wayne (Rooney) will operate from behind Robin (Van Persie) and Robin will play up front with Hernandez," Ferguson confirms to ITV Sport.
7.38pm"It is an honour to play against a team like United," he said. "It is not about the fact that we were excited about this fixture or not, it's all about the fact that we are going to play against a great team, maybe the biggest team which exists."
7.37pmWith just under 10 minutes until kick-off, let's have a look at what Cluj coach Ioan Andone told BBC Sport prior to this match...
7.34pmA graphic of the United team suggests that they may start with a 4-4-2 diamond formation. Rooney at the top behind Hernandez and Van Persie, with Fletcher sitting in front of the defence.
7.31pmJust being treated to shots of the pitch and the groundstaff are watering it quite a lot at the moment. Should make for some slick passing football.
7.26pmGoing back to the United team, it's strange to see them lineup with no wide players. Makes me wonder whether Rooney will be asked to play out on the right at times. He's done that in the past after all.
7.20pmHowever, looking at their scores so far this season, it would appear that Kapetanos could well be the danger man. He has found the net on six occasions in all competitions. And with United's defensive frailties, he may fancy his chances tonight.
7.16pmHurrah! There's your starting lineup Cluj supporters. I have to confess that my knowledge of those players is not the best. Although, I did once sign Sepsi on Football Manager! He was solid enough. Hope that helps!
7.10pmStill awaiting that Cluj team news. Beavering away but to no avail as yet.
7.05pmReports from the ground have claimed that United players have been clapped on to the pitch by Cluj supporters as they start their warm-up. That's something they will not be used to from the opposition faithful!
7.02pmThe record books show that Alan Smith and David Bellion were among the goalscorers against Bucharest. Players that are sure to still be giving United supporters nightmares!
7.00pmMeanwhile, United have faced Romanian opponents twice in this competition. Last season they defeated Otelul Galati 2-0 both home and away. Also, back in 2004 they beat Dinamo Bucharest 5-1 on aggregate in the third qualifying round.
6.56pmIn all seriousness though, Cluj have faced English opposition before. You may remember in 2008 that they faced Chelsea in the group stages. They lost 2-1 at Stamford Bridge courtesy of goals from Nicolas Anelka and Didier Drogba, while at home they claimed a credible 0-0 draw.
6.54pmWhile we wait, let's look back on previous matches between these two sides. Well there aren't any - that was quick wasn't it?!
6.50pmStill awaiting confirmation of the Cluj team. Will bring in to you as soon as we have it...
6.45pmWell that's rather attacking from Mr Ferguson. There's not much width, but he has three attackers in Rooney, Hernandez and Van Persie. Cleverley and Anderson also like to get forward. Should make for an exciting match.
6.44pmUnited X1: De Gea; Rafael, Ferdinand, Evans, Evra; Anderson Fletcher Cleverley; Rooney, Hernandez, Van Persie
6.43pmAlthough I have no idea why! Sorry. Anyway, enough of my ramblings, let's bring you some team news...
6.39pmOnly joking all you diehard Cluj fans, I've got plenty of facts about your club in the bank! For example did you know that their nickname is the Railwaymen?!
6.36pmEvening all. Well this is a test of my European football knowledge. CFR Cluj. Any ideas?!