Keane said on Sky News
"I'm looking forward to the next few years I have with the club and I'm really delighted to be back amongst the lads again. I have to say, it's like I never left. The lads have been spot on, the usual, and every fan I've met so far has been absolutely brilliant to me.
"I don't think I needed convincing to leave Liverpool. For whatever reason things didn't work out for me up there. That's life. And sometimes you just have to accept that and get on with it.
"I was chasing a dream, the team I supported as a kid, as a kid growing up you always want to play for the team you support. But sometimes the grass is not always greener on the other side and that's been the case. I'm back now. That is the past and I am looking to the future."