Collymore has been linked with moves to VfB Stuttgart and Paris St Germain since being told by City boss Jim Jefferies he no longer has a future there.

But now runaway Scottish Premier League leaders Celtic are believed to be interested in signing the striker, with Bradford chairman Geoffrey Richmond confirming Jefferies was keen on taking Tommy Johnson in exchange.

Collymore could not be more delighted if there was a chance of linking up with O'Neill, his former manager at Leicester.

"I've gone on record many times saying Martin O'Neill, for me, is the best manager in the UK - with the obvious exception of Sir Alex Ferguson," said Collymore.

"I thoroughly enjoyed working with him and his staff (at Leicester) so it is a move which would definitely appeal, although I haven't heard anything officially or unoffically, so we will have to wait and see."

Sheffield United and Swindon have attempted to lure him away from Valley Parade on a loan deal.

But Collymore said: "I have heard about other offers, but some of them have been rather insulting and from people trying to do a little bit of publicity seeking.

"I've always said all along the only move I would make is one which would be beneficial to my football career and at the highest level.

"The fact it's Celtic Football Club, who are huge and doing very well, with two or three people I know up there, as well as Martin, is appealing.

"It's a massive club and geared for success, so if something happened it would be thumbs up from me."