Sunderland have been dealt a blow after it was revealed striker Kevin Phillips could be out for six weeks after a hernia operation.

Phillips went under the surgeon's knife after being troubled by the injury following the draw with Manchester United on 31 August.

Sunderland boss Peter Reid told the club's website: "It's disappointing for Kevin, but it's one of those things where we thought it would be best to get the operation done straight away."

He added: "It's difficult to put a time limit on things like this but if all goes according to plan he should only be out for three to six weeks.

"We just felt that it was important to have the problem dealt with straight away."

Reid's new signing Marcus Stewart will step into Phillips' place against Middlesbrough, partnering Sunderland's other fresh face Tore Andre Flo.

Phillips' injury is not connected to the stomach and groin problems which plagued him last season.

The England striker underwent summer surgery to cure that problem after playing through the pain barrier in Sunderland's battle to avoid relegation.