Roy Keane has hinted his future as Sunderland boss may not be certain after the club's defeat by Bolton saw them slip into the relegation zone.
Defensive errors triggered Saturday's 4-1 loss after which some fans at the Stadium of Light fans booed his players - but Keane took full responsibility.
"I ask myself every day if I'm the right man for Sunderland," he said.
"I asked myself this morning, and I said I was. Sunday morning, if the answer's no, we'll have to look at it."
The Black Cats had taken an early lead through Djibril Cisse's low finish but Bolton soon hit back through Matt Taylor and Gary Cahill goals, while Johan Elmander's double either side of half time sealed a comprehensive victory.
Sunderland now lie 18th having lost five of their last six Premier League matches.
Keane added: "I have to be honest in my assessment. It's not about what's best for Roy Keane. It's Sunderland football club.
I might wake up on Monday morning and think I'm the right man. On Tuesday it might be different
"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 today and the run we're on and everything else."
Despite glaring errors from Danny Collins and captain Dean Whitehead on Saturday which led to Elmander's goals, Keane insisted he was not angry with his players.
"I look at what these lads have done over the last two and a bit years and they've been absolutely brilliant," he said.
"I can't legislate for individual mistakes so stuff like that doesn't make me angry.
"We play with such innocence we make it hard for ourselves and we seem to get punished for every mistake we make.
"It's such a harsh world. When you get in front you've certainly got to make sure you don't lose the game."
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