Manchester City manager Pep Guardiola has admitted that "it is not easy" to find a replacement midfielder for Fernandinho.
The Brazil international has started 30 matches for the Citizens this term, 24 of those in the Premier League, and his absence was felt when sitting out the defeats to Leicester City and Crystal Palace in December.
Guardiola has been seeking a back-up option over the past year, but the Catalan has missed out on top targets Jorginho, Frenkie de Jong and Fred.
Lyon ace Tanguy Ndombele is reportedly the next name on City's list, though Guardiola says that it is difficult finding the right player.
"We have some options but today it is not easy to find and buy the players," he is quoted as saying by Goal.com. "We have spoken many times about that. We are trying to help Fernandinho in that position.
"It's not close. But the transfer window is over, until the summer we have time. No problem. Always I am optimistic."
Guardiola fielded Fernandinho in central defence for the 3-1 win over Arsenal last weekend - a position in which the former Barcelona boss can see the 33-year-old operating more frequently in the future.
"I am pretty sure he can play in that position," Guardiola added. "He's fast, he's strong in the air and when he has the football in front of him he sees the passes inside, his switch of play is excellent.
"He is intelligent to [know when to] go forwards and go backwards, he understands everything. He has to train more at it, but I think he can do it. But of course, his position is a midfield player."
Fernandinho joined City from Shakhtar Donetsk in a £34m transfer five-and-a-half years ago.