Manchester City assistant manager Mark Bowen has revealed Michael Johnson is having problems coping with the mental challenges of the game.
The England Under 21 international has been plagued by a pelvic injury which has hampered his progress over the last year.
The injury has restricted Johnson to just three Premier League starts this season and there have been rumours over the player's fitness, attitude and lifestyle away from football.
Bowen admits Johnson's injury problems have been affecting him, but he has backed him to come through his troubles.
"Michael is a young lad who has been unlucky," said Bowen. "He has had a nagging injury that has held him back. When Michael in on the training ground and is focused he is a fantastic asset for this club.
"When young players have been in and out of action as long as he has it can mess your mind up a little bit because they just want to be out there playing.
"He has just got to be strong, fight through it, train hard and get back in the team.
"In the early part of the season he was a big player for us and we miss him."