Avram Grant believes that Andriy Shevchenko is struggling to recover from the shock of being left on the substititues bench by previous Chelsea manager Jose Mourinho.
Shevchenko has failed to live up to his £30m price tag since his move from Milan last year and Mourinho quickly appeared to lose faith with the striker.
Mourinho has since departed and Grant has taken over, but Shevchenko is still stuck on the sidelines at Stamford Bridge.
The 31-year-old has been reduced to a bit part role, scoring only once this season and making occasional substitute appearances.
“I prefer only to say that he was not at his best from the beginning of the year but there are many reasons for this,” Grant said.
“You never know if it is because of the mental side that the player doesn’t look so good in the physical side, or if it has come from the physical side. Sometimes it is both.
“We are talking about professional players. They need to handle everything. We are not baby-sitters of the players.
“We tried to help him as we try to help other players. But the players feel they need to help themselves. We have a big squad and we will need everybody, including Andriy Shevchenko.”
Grant still believes Shevchenko can recapture the form that made him the most feared striker in Europe.
“Andriy was a very good player and he is still a very good player, even if he is not playing now,” he said.
“I know from my experience there are some periods when players are not at their best, but it doesn’t mean they are finished.
“Some players who are not in the team can come back well. That is what it will be with Andriy. He is a very good player with a good attitude.”