Meanwhile, Thomas Frank's side kept their perfect start to the summer going with a 3-1 success against Watford over the weekend.
Jesse Lingard may have proved his worth to Ole Gunnar Solskjaer with a fourth-minute opener against QPR during Man United's second friendly of the summer, but the joy was short-lived for the Red Devils as Charlie Austin levelled the tie with six minutes on the clock.
United would proceed to be rocked by a six-minute flurry of QPR goals, with Lyndon Dykes netting twice either side of Moses Odubajo's finish, and Solskjaer's side could only make the net ripple once more through Anthony Elanga as QPR ran out 4-2 winners.
Pre-season results are never a good indication of how a team's season may play out - and United did spoil Wayne Rooney's reunion party with a 2-1 win over Derby County earlier this month - but conceding four to QPR would not have done the confidence of Solskjaer's veterans and youngsters any favours.
However, the biggest news out of the United camp recently was undoubtedly the confirmed arrival of Jadon Sancho from Borussia Dortmund, while progress is also believed to have been made in their efforts to sign Raphael Varane from Real Madrid.
Preston North End and Everton also lie in wait for Man United before their Premier League campaign begins against old foes Leeds United, but with fans set to make a long-awaited return to Old Trafford this week, the visit of Brentford is not to be taken lightly.
Brentford have started pre-season as they mean to go on in their first-ever Premier League venture, with Frank's side claiming four victories from four during away clashes with Wimbledon, Boreham Wood, Cambridge United and Watford so far.
In a turn of events that surprised few, much-admired striker Ivan Toney bagged a brace against Watford at the weekend while Halil Dervisoglu also found the back of the net in that training ground encounter as Henry Wise's penalty proved to be a simple consolation.
Frank unsurprisingly fielded a large contingent of first-team players as the Bees stung the Hornets at the weekend, with the Brentford coach not prepared to see his side's momentum take an unnecessary hit before they ply their trade in the top tier of English football.
West Ham United, Southend United and Valencia also lie in wait for Brentford before the Premier League season begins, and one can imagine what a positive result at Old Trafford - albeit a pre-season one - would do for the Bees' confidence.
Man United and Brentford last locked horns competitively back in 1975 - an EFL Cup encounter which United won 2-1 - and the most recent top-flight encounter between the two clubs ended goalless back in 1947.
Some of the Red Devils' experienced international contingent will make their returns to pre-season training this week, but with the batteries needing more time to be recharged, he will be working with the same group of players for Wednesday's battle.
It would not be a surprise to see Lingard earn another start as the Red Devils seek to fend off interest from West Ham United, while Elanga and James Garner will hope to impress the Old Trafford crowd.
Meanwhile, Brentford have welcomed a quartet of arrivals to the club over the past week, as a deal for Kristoffer Ajer was struck with Celtic while Frank Onyeka has arrived from FC Midtjylland, and the former featured for 45 minutes at the weekend.
Matthew Cox and Myles Peart-Harris have arrived from Wimbledon and Chelsea respectively, while Mathias Jensen, Pontus Jansson and Christian Norgaard will soon return following their Euro 2020 exploits.
Manchester United possible starting lineup:
Heaton; Wan-Bissaka, Mengi, Tuanzebe, Williams; Garner, Matic, Mata; Elanga, Greenwood, Lingard
Brentford possible starting lineup:
Raya; Ajer, Pinnock, Goode; Stevens, Janelt, Oksanen, Thompson; Canos, Toney, Valencia
We say: Manchester United 2-2 Brentford
With the inspired Toney leading the line in front of a buoyant Old Trafford crowd, Brentford ought to punish an inexperienced United backline that is certainly not impenetrable - as proved by QPR.
Fresh legs either side of the half-time break will lead to an energetic encounter between two sides with different goals to fulfil in the Premier League season, and we can envisage an entertaining draw being played out on the red side of Manchester.