The Gunners head to Old Trafford on Sunday two points ahead of United and out to cement automatic qualification for the Champions League group stages.
Finishing third would, statistically at least, represent an improvement for Arsenal, who hold a game in hand, and could retain the FA Cup if they beat Aston Villa at Wembley on May 30.
Wenger, though, knows full well none of the title hopefuls can afford to stand still as they look to sustain a much-improved effort to reel in runaway champions Chelsea in 2015/2016.
"We feel we have made progress, but we have a good opportunity to show that on Sunday because in every game that is questioned," said Wenger, whose side were beaten 1-0 at home by Swansea on Monday night - a first league defeat since February 7.
"That is what is at stake until the end of the season, to show that we can be stronger next year.
"We made 79 points last year, that was quite a good total, but it was not enough to finish in the top three.
"Only one thing shows you have made progress and that is the continuity in your performances, and that you have a good level of cohesion.
"Since January we have produced consistent performances and we have also been very strong away from home, and again on Sunday we have an opportunity to show that we have made progress."
Following a slow start under new manager Lois van Gaal, United have clawed their way back into the top four as they bid to return to the Champions League, which could need a play-off in August.
Wenger is in no doubt United will soon be a force to be reckoned with again as they target a first trophy since Sir Alex Ferguson's departure.
"They have made progress since the start of the season, and will show that next season," said Wenger.
"It looks like they have improved quality-wise from the start to now."
United have already recruited Holland international Memphis Depay from PSV Eindhoven and have been linked with big-money moves for the likes of Gareth Bale and Harry Kane.
Wenger would not be surprised to see plenty of summer transfer activity at Old Trafford.
"It looks to me like they are on the market because every player I am offered, I am told Man United are on the case as well," he said.
"It looks like they are very active and you expect them to come back with some strong buys, but they already have a very strong squad
If you look at their squad, it's top quality already."
Source : PA