England defender Rio Ferdinand will miss Manchester United's match at Burnley on Wednesday and is likely to be sidelined for at least another two weeks as the champions battle to cope with an early season injury crisis.
Ferdinand went for a scan on his injured thigh on Monday after missing United's opening game against Birmingham City, which they won 1-0 at Old Trafford on Sunday.
Ferdinand's injury comes at a bad time for United with his defensive partner Nemanja Vidic (calf) also out of the visit to Burnley while reserve defender Jonny Evans limped off after 74 minutes with a groin injury.
Goalkeeper Edwin van der Sar (broken hand), Gary Neville (groin) and Rafael da Silva (shoulder) are also sidelined.
Manager Alex Ferguson, whose side are chasing an unprecedented fourth successive League title, told the club's television channel MUTV that it is not all doom and gloom at Old Trafford.
"Nemanja Vidic is back training and hopefully we'll get him back for next Saturday at Wigan.
"We've had a hard time with injuries in our defence over the last two seasons but we've got capable people to fill in."
Until the late 1960s, matches between the two clubs, whose grounds are only 21 miles (33kms) apart, were usually fiercely contested derbies, but Burnley have not beaten United in 17 matches since September 1968.
Burnley, back in the top flight for the first time since 1976, started their season with a 2-0 defeat at Stoke City on Saturday and will cause one of the shocks of the season if they beat United.
Five other Premier League matches are being played during midweek with Sunderland hosting Chelsea and Wigan Athletic playing Wolves on Tuesday. On Wednesday, Birmingham face Portsmouth, Tottenham Hotspur travel to Hull City and Liverpool are at home to Stoke City.
Chelsea left it late to get their title challenge underway with a flukey stoppage-time winner from Didier Drogba giving them a 2-1 win over Hull on Saturday while Sunderland also started with a win, beating Bolton Wanderers 1-0 with a debut goal from Darren Bent.
Bent's former club Tottenham made their best start to a season for four years with their 2-1 win over Liverpool and will now attempt to build on that by beating Hull, less than three weeks after beating them 3-0 in Beijing to win the Premier League's Asia Cup trophy.