Manchester United manager David Moyes has warned Nemanja Vidic that he faces a fight to win back his place in the starting line-up.
The United captain is fit to play in Wednesday's Capital One Cup quarter-final at Stoke City, after missing the last two matches through injury.
During the Serbian's absence Moyes' side have kept clean sheets in both matches.
Jonny Evans and Phil Jones impressed at centre-back during the 1-0 win over Shakhtar Donestk and the 3-0 victory over Aston Villa.
With Vidic's increasing injury problems and the fact that his centre-back partner, Rio Ferdinand, is now 35, Moyes claimed that the there maybe a changing of the guard.
"Nemanja is just about ready to play now," Moyes told a press conference on Tuesday.
"But we have five centre-halves. We can use Phil Jones, Chris Smalling, Jonny Evans, Rio Ferdinand and him.
"There is competition for places there and you are going to have to play well to stay in the team."
Moyes will be without striker Robin van Persie (thigh) and midfielder Michael Carrick (Achilles) at Stoke, while there are doubts over Javier Hernandez (head) and Shinji Kagawa (illness).
