Rio Ferdinand is set to miss Manchester United's Premier League opener at Everton on Monday night with a groin injury that could keep him out for a month.
The former England captain is understood to have suffered the injury during training on Friday. United manager Sir Alex Ferguson is already stretched in defence for the trip to Goodison Park, as he is without Chris Smalling, Phil Jones and Jonny Evans.
It means that Michael Carrick is in line to play at centre-back alongside Nemanja Vidic, who will be making his first competitive appearance for United since suffering a cruciate knee ligament injury against FC Basel in the Champions League last December.
Northern Ireland centre-back Evans has not played all summer after ankle surgery, although he is close to a return. Smalling is out until mid-October following an operation on a broken metatarsal, while Jones - who has been troubled by back spasms - has been told by United's medical team to rest for a month.
Ferguson is hopeful that midfielder Darren Fletcher is getting closer to a comeback. The Scotland midfielder, 28, has been out of action since last December, when United revealed he was suffering from the chronic bowel condition ulcerative colitis.
But he played his first full 90 minutes for nine months as United beat Stoke at Nantwich on Saturday morning in the Under-21 Premier League - which allows sides to field three over-age outfield players.
That came after a surprise 30-minute appearance in a friendly against Aberdeen at Pittodrie on Wednesday.