ew Birmingham keeper Ben Foster insists his relationship with Sir Alex Ferguson remains undamaged after leaving Manchester United.[LNB] Foster has made a £6million switch to St Andrew's in a bid to play regular first-team football after becoming the third-choice keeper at Old Trafford.[LNB]His move down the pecking order ended his hopes of being part of England's squad for the 2010 World Cup finals.[LNB]But Foster has nothing but admiration for Ferguson despite starting only two first-team games since playing back-to-back internationals against Belarus and Brazil last autumn.[LNB]Foster said: "Had my relationship with Sir Alex become strained by the end? No, definitely not.[LNB]"I've read quite a few things saying that we had a massive barney after the Sunderland game. A barney involves two people talking. It was mainly just one person![LNB]"But the relationship was definitely not strained. Sir Alex has been fantastic with me and I've read some nice things he said the other day which is fantastic to hear.[LNB]"It gives you a boost. You never have to say anything when a player leaves his club. I got on with the manager really well up until the end, which unfortunately had to come."[LNB]Foster concedes he had to leave United to further his career.[LNB]He said: "I've been at United five years, two of them on loan at Watford. I've really enjoyed my time there. I've been out on loan for a few different teams and seen that side of football.[LNB]"To be at Manchester United is a different world but the last couple of years have been at up and down for me, in and out of the team.[LNB]"You come to a point in your career when you realise it's not going for you at a certain club and that time has come.[LNB]"I'm delighted to join Birmingham. It's a team with ambition, a team looking to continue on from last season's progress and I'm just happy to be here.[LNB]"I know I was at Manchester United, the biggest club in the world, but I don't enjoy not playing regular first-team football.[LNB]"Training is all good but you've got to have something to look forward to and that is what is on offer now."