Arsene Wenger accepts there were probably times when Arsenal midfielder Jack Wilshere doubted whether he would ever play again.
The England international finally returned to full training yesterday after a niggling ankle injury sidelined him for the whole of last season, also ruling him out of contention for Euro 2012.
Wenger, though, will take no chances with the 20-year-old, who is likely to have a few reserve outings before being considered for first-team action.
The Gunners boss understands Wilshere has been through a testing spell of "highs and lows" during his 14-month rehabilitation, a spell which saw him need further surgery just when a recovery appeared on the horizon.
"When you are so young and out for 14 months that is a good test for your mental strength," said Wenger.
"On that front he has been absolutely brilliant because he had not only ankle surgery, but when he thought that was over he had knee surgery. He handled that very well, I must say.
"I refused to give up, because he is a 19-year-old boy, so I always thought he would come back.
"I am not medically expert enough to know how big the damage was in his ankle. It never crossed my mind. Has it crossed his mind? Only he can answer that - I think, yes.
"Jack, though, has always been with a good level of confidence.
"I believe what he has gone through will make him even stronger."
Wenger continued: "Jack had ups and downs, and many downs because he had a few setbacks, but he dealt with it very well, especially in the last three months he was highly focused every day.
"Jack was in every day very early and worked all day through. He is rewarded now with a good condition."
Wilshere will be reintegrated into the first team slowly, with a run-out for the reserves likely in 10 days' time.
"We will see how he responds to the training now," said Wenger, who takes his side to Barclays Premier League champions Manchester City on Sunday.
"We will have to be a bit patient, a bit cautious, because when a guy has been out or 14 months it takes a while to get back to match fitness.
"Jack is fit to practice and play, but to put high-level performances in takes time.
"He will need a few games in the reserves."
Combative midfielder Emmanuel Frimpong is also closing in on a return, having been sidelined by a serious knee injury suffered while on loan at Wolves in February.
However, goalkeeper Wojciech Szczesny will again be sidelined by the ankle problem which forced him out of the midweek Champions League win in Montpellier.
Wenger feels the Gunners can head to the Etihad Stadium in confident mood, and does not expect the Blues' late defeat at Real Madrid to play a major impact.
"I expect them to be focused and play well, but it was a disappointment for them of course. It always takes a little bit away from you," he said.
"But on our side, let's not have any speculation of the weakness or strength of them, let's focus on us to be at our best.
"If we are at our best I think we have a great chance to get a good result there."
Arsenal have impressed during their unbeaten start to the new domestic campaign, conceding just one goal.
However, the next set of fixtures will test just how far that resurgence can go, with Chelsea coming to Emirates Stadium next weekend.
"It will tell us a lot about our quality and how we handle the big games will decide how well we do in the championship," Wenger said.