Roy Keane has placed doubt on his ability to continue as manager of Sunderland, after watching his side drop into the relegation zone on Saturday. After 15 games Sunderland are third from bottom with 15 points from four wins and three draws, and were thrashed 4-1 at home by Bolton Wanderers yesterday.

"I ask myself every single day if I am the right man for Sunderland. I asked myself this morning and said I was," Keane, whose contract expires at the end of the season, said.

"Tomorrow morning if the answer is 'No' we will have to look at it. It's not about what's best for Roy Keane. It's what's best for Sunderland Football Club. I might wake up on Monday morning and think I'm the right man. On Tuesday it might be different.

"I'm the manager of this football club and ultimately I'm responsible and I've never shied away from that. That's part of being a manager and that's why I take full responsibility for the run we're on and everything else."

After spending nearly £70 million in the transfer market, Sunderland are struggling to keep pace in the highly competitive Premier League, having won just one of their last seven games.

"I can't sit here and say I've not had the backing," Keane added. "I have brought in loads of players and I have absolutely no excuses.

"We've been very poor and the goals we have conceded recently would make it impossible to win any game of football, let alone in the Premier League.

"It is not good enough. We play with such innocence we make it hard for ourselves and we get punished for every mistake we make."