Republic of Ireland defender Andy O'Brien claims Portsmouth manager Harry Redknapp treated him "like a mug" before his move to Bolton in the summer.

O'Brien claims he was frozen out at Fratton Park after being signed by previous manager Alain Perrin in 2005.  The 28-year-old's stay on the south coast turned sour when Redknapp returned mid-season from Southampton.

O'Brien spent almost the whole of last term in the reserves, losing his place in the international squad after making just three league appearances.

He was given a fresh start at Bolton and has prospered under new manager Gary Megson, rebuilding his confidence and earning an international recall.

The ex-Newcastle and Bradford defender praised Megson for showing faith in him and although he also credits Redknapp with helping to revive his career, his comments were laden with irony.

"I think I've got Harry Redknapp to thank a lot for my performances since I came to this club," he said. "I say that a little sarcastically because he treated me like a mug for 18 months and it certainly taught me not to take things for granted; that when you get another opportunity you've got to make the most of it.

"You get frustrated and your confidence dips when you're in that situation, but if you look at my stats in terms of the amount of games I've played and at the level I've played them, I think it shows I can do a job.

"I'm 28 now so I'm not past my best. I'm feeling confident again because the manager's supported me and that's 50 peer cent of the battle really."

Megson has rotated his squad since taking over from Sammy Lee in October, giving his fringe players a chance to impress in the Uefa Cup.

The former West Brom and Leicester boss has been rewarded with a run of just two defeats in 10 games, taking Wanderers out of the relegation zone and putting them on the verge of the Uefa Cup knockout stages.

"When a new manager comes in, players that maybe haven't been involved start afresh and players that are in the team have to justify their position," said O'Brien. "It's been a good ingredient for the success of the club.

"It's fair to say I've been on the receiving end of a new manager coming in, and football is a game about opinions, but fair play to the manager.

"He's given everybody a chance and the players are responding by giving him and the club the right results at the moment.

"That's what we've brought him in to do and that's what he's achieving so far."