The Spaniard is out of Saturday’s home clash with Leicester and the trips to Arsenal and Chelsea as he faces up to six weeks on the sidelines alongside central defender Wes Brown, who returned to action last weekend, but has suffered a setback in his recovery from his own knee problem.
Midfielder Jack Rodwell (hamstring) is still out, but defender John O’Shea has recovered from a knee injury and midfielder Emanuele Giaccherini is available for the first time since February after finally shaking off an ankle problem.
Matty James could be out until next year for Leicester after suffering cruciate knee ligament damage last week.
Scans confirmed the severity of the injury, which happened in the Foxes’ 2-0 win over Southampton, and the midfielder will have an operation on Tuesday and is expected to be out for between six and nine months.
David Nugent is also out of the trip to Sunderland with a calf problem but Andy King (hamstring) is available for boss Nigel Pearson.