Victor Lindelof and Lisandro Martinez were ruled out for at least a month, two days before Thursday's helter-skelter 4-3 defeat at Chelsea, and two more centre-backs also have fitness issues following the trip to London.
Raphael Varane was substituted at half-time for the second game in a row after limping in the closing stages of the first half.
The Frenchman was replaced by Jonny Evans – back after missing the Liverpool and Brentford games in March – for the second period but the 36-year-old could only manage a 21-minute cameo before Willy Kambwala had to be called upon.