Morgan, a virtual ever-present this season, was forced out during the midweek defeat at Watford and is the latest in a catalogue of injury setbacks to hit the Blades' promotion hopes.

chris morgan

Blackwell said: "We're looking at between three and five weeks as he's got a five centimetre tear in his rib muscle. This is a massive blow, especially as we have lost (Kyle) Walker and (Matthew) Kilgallon in the last few weeks.

"I've never known anything like the number of injuries we've had at the club this season. Just as we thought we had got it sorted we now need another centre-half and possibly a right-back too."

The Blades sold central defender Kilgallon to Sunderland for an undisclosed fee while Walker, loaned back to the club following his summer sale to Tottenham, was recalled to White Hart Lane earlier this week.

Centre-half Marcel Seip, on loan from Plymouth, and fellow defender Andrew Taylor are sidelined with hamstring injuries and Gary Naysmith is still working his way back from a long-term knee problem.

Source: Team Talk