Arsene Wenger said Serge Gnabry "lacked a bit" while at Arsenal after the former Gunners winger scored twice in Bayern Munich's 3-0 Champions League win at Chelsea .
Gnabry's quickfire brace set the reigning Bundesliga champions on their way to a comprehensive first-leg victory in their last-16 clash at Stamford Bridge on Tuesday.
The 24-year-old's match-winning performance came after he scored four goals against Tottenham in Bayern's 7-2 victory in London back in October.
Gnabry's resurgence raises questions over Arsenal's failure to hold onto him when he joined Werder Bremen in 2016 following a disappointing loan spell at West Brom.
But Wenger, who was Arsenal's manager at the time, said Gnabry had lacked application while at the Emirates.
He admitted the Gunners were powerless to keep a player who had been tipped for a bright future after joining Arsenal from Stuttgart for just £100,000 at the age of 16.
And he accused Bayern of "stealing" Gnabry from under Arsenal's noses, claiming a deal was done for him to join the German giants even before he left the Gunners for £4.5million.
"This guy, he has no real limitations - it’s more how much does he want to suffer,’ Wenger said of Gnabry as the former Gunners boss appeared as a pundit on beIN Sports.
‘Because he has pace, power, technical ability - he’s very intelligent.
"Sometimes he looks for the easy way in football.That’s what was his problem.
"He lacked a bit. I gave him to West Brom, it didn’t work out at all. In fairness I think we had an agreement with him but Bayern stole him away from Werder Bremen.
‘He’s a good player, he needs good players of course, like everybody, but he has individual ability and collective ability.
"We had an agreement with him but because he didn’t play at West Brom I let him go with the under-21s in the summer with the German national team.
"He did very well of course, he was fresh. We had prepared him for us to sign his new contract but then suddenly he wanted to go to Werder Bremen."
Bayern signed German international Gnabry for £7.2m from Werder Bremen in 2017, and Wenger said: "It was not Werder Bremen that bought him, it was Munich that bought him.
"Because six months later or less than one year later he moved from Bremen to Bayern, but it was a done deal before."
Asked if Arsenal could have prevented Gnabry from leaving for Werder Bremen, Wenger said: "No, because he was at the end of his contract and we thought that he would stay, because he told he would stay."
