Rio Ferdinand has been ruled out until after the international break as Manchester United's central defensive crisis continues.

Sir Alex Ferguson had raised hopes that the 33-year-old would be back for Sunday's trip to Southampton. But it is understood the earliest he will return now is United's meeting with Wigan Athletic at Old Trafford on 15 September.

Ferdinand is suffering a groin injury that has caused him to miss United's opening two games of the season. While Jonny Evans did return to the bench for Saturday's 3-2 win over Fulham at Old Trafford and may be ready to partner Nemanja Vidic at St Mary's, Ferdinand is joined by Chris Smalling, who has a foot injury, and Phil Jones – a back problem – to make three of Ferguson's first-choice central defenders unavailable.