Nicklas Bendtner has turned a corner and is keen to prove his doubters wrong at Old Trafford on Wednesday, according to Wolfsburg manager Dieter Hecking.
Bendtner was regarded as a good young prospect when Arsenal signed him in 2004, but 10 years later he left the club having started just 41 Premier League games.
The Dane's cocksure personality made him a divisive figure among followers of the Premier League and manager Arsene Wenger loaned the player out three times.
Bendtner had a string of off the field problems too. He was fined for making an unauthorised trip to Denmark during his final year at the club, was suspended for six months by the Danish Football Federation after being caught drink driving and he was also cautioned by police two years ago for smashing a door at his Hertfordshire home.
His troubles continued at Wolfsburg, where he was made to train on his own after falling out with Hecking, but the 27-year-old scored a vital equaliser and the winning penalty in the club's DFL-Supercup victory over Bayern Munich in August and is now a key squad member according to his manager.
"He has reacted very well. I have seen that in training," Hecking said on the eve of Wolfsburg's Champions League match at Manchester United. "He did have problems before but in his time at Wolfsburg he has come on a lot.
"Certainly in the last four to six weeks I have seen more development from him. He is on the right track. That is clear.
"He shows that in training, perhaps with less of the extravagance that he showed in England before, so I think he is on the right track and he will definitely be keen to play on Wednesday."
Bendtner has started just one league match this season, but Wolfsburg are in poor form and Hecking could therefore recall the striker for the Group B match.
Unlike United, Wolfsburg began their Champions League campaign with a win against CSKA Moscow. And Hecking is looking to make Louis van Gaal's life even more difficult by beating the hosts on Wednesday.
"They lost their first game, that creates a bit of pressure on United, but I think they are capable of dealing with that," he said.
"It is up to us to increase the pressure on them on Wednesday. That is a big if. We will have to wait and see what happens."
Wolfsburg's chastening 5-1 defeat to Bayern Munich last week -- in which Robert Lewandowski scored five times in nine minutes -- suggests they are there for the taking.
A dark cloud also hangs over the club because of the crisis engulfing Volkswagen.
The German car manufacturer, which owns the Bundesliga club, is facing a potential multi-billion pound fine for cheating emissions tests.
Hecking insists the crisis is having no impact on him or his players, however.
"It is a matter of interest but it doesn't have any effect on the club," he said. "Volkswagen is independent and the club is an independent organisation.
"It hasn't affected the team or our performances. We are following events but that is it."