The home team will look to pull off one of the round's most notable upsets, although they face an uphill challenge as they host a side who sit 25 places ahead of them in the Scottish football pyramid.
Forfar Athletic come into this game having defeated Linlithgow Rose and Edinburgh City to reach the final 16.
Neither of the victories were comfortable, though, as they only defeated the sixth-tier outfit in extra time, when a Martyn Fotheringham goal and a Jordan Allan brace sealed a seemingly dominant 4-1 victory after 120 minutes.
They then required penalties to get past the side from the Scottish capital, as Roberto Nditi equalised in the 94th minute of regulation time to take the tie to extra time, before Daniel Scally sealed the shootout win with a penalty rifled into the top corner.
Despite making it to this stage of the competition, Friday's hosts have had a poor league campaign, currently sitting at the foot of the Scottish League One table having won just two of their 17 league games so far this season.
They suffered a 3-1 defeat away at Airdieonians most recently, as the hosts led after just two minutes through a Hamish Thomson own goal.
The hosts will look to break their dismal run of form with what would be a major upset on Friday, as they welcome Scottish Premiership side Dundee United.
On the contrary, Micky Mellon's side have put together a strong run of form, winning their last three matches in all competitions and remaining unbeaten in five games.
That run included a 2-1 win over Partick Thistle in the third round of the Scottish Cup, as the second-tier side led through Scott Tiffoney before Lawrence Shankland equalised with 10 minutes to go, and Nicky Clark netted the winner deep into added time to fire the Tangerines to the last 16.
Most recently, Marc McNulty fired Mellon's men to a 1-0 victory over Hamilton Academical in the first game of the second phase of the Scottish Premiership, after they missed out on the Championship group by just one point.
Their winning run, along with a commendable 0-0 draw with Celtic, has set the Tangerines up for a solid end to the season, and they will be hopeful of qualifying for the quarter-final stage with a win over a struggling Forfar Athletic side on Friday evening.
Despite being shown a red card in the previous round against Edinburgh City, Forfar Athletic defender Hamish Thomson will be available for selection on Friday, as he served the suspension in the following league draw with Peterhead.
His place could be in doubt though, having conceded five goals in the two games since his return to the side, including the early own goal in the 3-1 loss to Airdrieonians.
They will be boosted by the return of left-back Bernard Coll, who served a suspension last time out for a red card shown in the 2-1 defeat to East Fife.
The Forfar line will be led by Jordan Allan, who has netted seven goals in all competitions this season, including three in their two Scottish Cup games to get to this stage.
Dundee United are expected to field a strong side on Friday, as they look to avoid a potential upset and book their place in the quarter-final stage.
That could see Marc McNulty and Lawrence Shankland partner up in attack, although Nicky Clark will be hoping that his 10 goals this season will secure him a place in the starting side after a spell on the bench.
Forfar Athletic possible starting lineup:
McCallum; Meechan, Thomson, Munro, Coll; MacKintosh, Holmes, Moore, Scally; Anderson; Allan
Dundee United possible starting lineup:
Mehmet; Smith, Reynolds, Edwards, Robson; Fuchs, Butcher, Harkes; Sporle; Shankland, McNulty
We say: Forfar Athletic 0-3 Dundee United
Coming in on the back of a strong run of form, we see the top-flight outfit recording a dominant victory on the road on Friday, easing past Forfar.
They have developed a strong back line which should limit the third-tier side to few chances, while they will create plenty of opportunities to break down the weak Forfar defence.