David Moyes has warned Nemanja Vidic he must fight for his Manchester United starting place amid strong competition.
The United captain is set to return to the squad having recovered from a small injury problem picked up against Newcastle in the 1-0 defeat earlier this month.
The Serbian international has been a critical player for United since he joined from Spartak Moscow in 2006, but United have impressed in his absence.
He's missed victories over Shakhtar Donetsk and Aston Villa, games in which United kept consecutive clean sheets.
In his place, Jonny Evans and Phil Jones kept out Christian Benteke and the Aston Villa attack at the weekend, and Moyes has warned his club captain that he faces a fight to get back into the side.
"Nemanja is just about ready to play now," Moyes told Sky Sports.
"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."
Vidic has suffered with injury trouble for the past two seasons, and United have been linked with a number of centre-halves for the upcoming January transfer window.
Vidic and Rio Ferdinand still remain first-choice for the defending Premier League champions, but age and fitness means Moyes needs strength in depth at the position.
And with five centre-backs to choose from, Moyes has plenty of options.