The Red Devils made three major signings in the summer, with 21-year-olds Aaron Wan-Bissaka and Daniel James arriving alongside Harry Maguire, who joined from Leicester City for a world-record fee for a defender.
Despite the acquisitions, a number of departures at Old Trafford has left Ole Gunnar Solskjaer's squad looking thin in some areas. Wenger said he is unsure whether the younger players at United are capable of filling the gaps and pushing the team on, per beIN Sports (h/t Robin Bairner of Goal):
"When you see Man United they are one of the examples where there is a potential there, but they have not found a collective way. Maybe these players are not mature enough to carry the team play of a team like Man United all together.
"That's the big question mark now. You feel there is something coming out but it's not ready. That's why I say when you watch them play they are not candidates to fight for the championship.
"Will they emulate what [Ryan] Giggs, [Paul] Scholes and [David] Beckham did over a number of years? Personally, I'm not convinced."
United have got off to a disappointing start to their Premier League season, taking five points from their first four games.
Although the Red Devils look thin in the midfield and attacking positions, Alex Shaw of ESPN was impressed by the manner in which the manager shipped players out and is seemingly happy to put his trust in youth:
That means academy stars like Mason Greenwood, Angel Gomes and Axel Tuanzebe are all likely to get regular games in the upcoming campaign, especially given United's involved in the UEFA Europa League.
Additionally, the two young players signed by United in the summer look set to be major successes, with neither Wan-Bissaka nor James daunted by the move to Old Trafford.
The former has been a colossal defensive presence at right-back and is seemingly a long-term fix to what was a problem position for United last term. Meanwhile, James has surprised many with his quick adjustment to Premier League football, netting three times in his first four games.
The winger carried his good form into the international break, where he netted for Wales:
After a disappointing 2018-19, United are seemingly willing to take a step backwards to move forward. The trust in younger players may mean an initial downturn in results, but Solskjaer will hope there are long-term benefits to some tyros being involved.
Wenger, who won the Premier League three times and seven FA Cups at Arsenal, was renowned for developing young talent during his early years in north London. The Frenchman left the Gunners after an illustrious 22-year stint in 2018 and has yet to return to management.