That is the assesment of Arsenal midfielder Mikel Arteta, after news that Wilshere needs yet another operation on his ankle.
Wilshere suffered a fracture in training in August and will have a small plate inserted into his left fibula.
And Arteta said: "Jack has had a lot of set-backs in his career but he has always shown character and enthusiasm to get back. He has an amazing career in front of him. The danger is that he doesn't believe it himself, he doesn't believe his body. He needs to trust himself."
Arsenal manager Arsene Wenger tried to stay positive, believing the midfielder can return before Christmas.
"It's still early in the season and he can be back in mid-December when there is still a long way to play," said Wenger. "This kind of injury is not a kind that can damage your career.
"It's a bone that needs a little clip in, nothing major. It's not a career-threatening injury. I think he's young enough to get over it. And his body will stabilise. I'm confident he will and that he can make a career his talent deserves."
GETTY
Arsenal midfielder Jack Wilshere is set to have a plate inserted into his left fibula
The new blow appeared to knock Wenger's hopes he could lead the north Londoners to a first success in the Champions League and he said: "We are ambitious, but we are not dreamers."
The Gunners face Croatia Zagreb tonight with the home side unbeaten in 41 matches, although they have failed to win their last 15 group games and have never made the knockout stage.
"The drive to win it is immense," said Wenger. "It has never been done at Arsenal. We were very close [losing to Barcelona in the 2006 final] but I am long enough in the job to know you have to be realistic."
While Wenger has been having a relatively stress-free time, his bitter rival Jose Mourinho at Chelsea has found himself under immense scrutiny following the champions' shocking start to the season.
Arsenal visit Chelsea on Saturday, but Wenger refused to reveal whether he was enjoying seeing his rival suffer.
Arsene Wenger manager profile
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"That's part of our job and I wouldn't say much more than that," said Wenger. "It is important that we focus on our game. In the Champions League you're quickly out if you don't start well.
"We know we have a vital game and it is important we focus on that."
Dinamo have now not lost in a formidable run of some 41 matches and last season they became the first team to go unbeaten through a Prva Liga campaign.
However, the Croatians have never previously qualified for the knockout stages and have endured a 15-game winless run in the competition proper.
Wenger said: "Croatian football produces always top level technical quality, that is their strength. We have to focus on our own performance and to beat them have to play at our best and without speculating on any weak link in a team that has not lost a game for 11 months."
