Roberto Mancini has admitted that taking a gamble on signing Owen Hargreaves has backfired.
The Italian brought the English midfielder to the Etihad Stadium after Hargreaves posted videos of himself training on YouTube in a bid to get signed up.
Hargreaves has only been able to make four appearances for City this season and is currently out of contention because of niggling injuries.
He is not expected to be offered a new contract when his current one-year deal comes to an end.
"We took a gamble on Owen because he was such a fantastic player," Mancini said.
"We thought we could try to get him fit in two or three months and then he would be able to play. But it hasn't worked out quite like that.
"When you have a player who hasn't played for two years and he starts to train every day there are small problems all the time. Problems in the knees or the hamstrings. So Owen hasn't been able to play when we have needed him.
However, Mancini didn't rule out the 31-year-old featuring in a blue shirt again, adding: "He may play again this season but he is not ready now. I hope eventually he will be able to play all the time. He deserves to, because he is a really nice guy."
City have brought in Roma midfielder David Pizarro on loan to provide cover in the midfield area in Hargreaves's place.