Nistelrooy out for another two months
The 28-year-old striker has missed the last three games after aggravating the problem against West Brom.
Boss Alex Ferguson had previously hoped he would return in January.
The Dutch striker is now looking at the first leg of the Champions League tie against AC Milan on February 23 for a possible return to the United team.
Ferguson said: "we don't want to force him when we don't need to and we hope to have him for the AC Milan game."




