Roy Keane has held talks with Celtic over their vacant manager's job, according to Republic of Ireland manager Martin O'Neill.

O'Neill confirmed on Thursday evening that his 42-year-old assistant has held informal talks with the Hoops, for whom he played briefly at the end of his career, after owner and majority shareholder Dermot Desmond had made contact.

O'Neill said: "I had a call the other day from Dermot Desmond wanting to speak to Roy if it was at all possible, and I mentioned it to Roy, of course.

"I am sure he was wanting to have a chat anyway because a club like Celtic might not come around too often.

"It was just a really informal chat, I think, but if you are asking me would I be really disappointed (if Keane was to depart)? Of course, if Roy was to leave us."

O'Neill's comments came minutes after he and Keane had put their players through their paces in an open training session at Aviva Stadium amid mounting speculation that the younger man is Celtic's top target in the search for Neil Lennon's replacement.

The Derry man admitted at the weekend that he would not stand in Keane's way if the call came, and while he insists nothing is yet decided, he is bracing himself for the departure of a man he brought back into the game following his appointment as Ireland boss in November last year.

Asked if Keane, whose odds with the bookmakers tumbled overnight, had been offered the job, O'Neill said: "I think it was really just informal chats."

Celtic later confirmed they are in talks with "a number of excellent candidates".

A statement said: "Following speculation concerning the manager's position at Celtic, the club can confirm that it is currently continuing its discussions with a number of excellent candidates.

"We will continue this process and select who we regard as the best appointment for Celtic. We will update our supporters as soon as this process is complete."

Keane last week played down the link with his former club, insisting he already had two jobs, but admitted he would sit down with O'Neill and John Delaney, chief executive of the Football Association of Ireland, if the call came.

O'Neill himself, of course, enjoyed a hugely successful five years in charge at Parkhead, but asked if it was too good an opportunity to turn down, he said: "I don't know. It's a very big job obviously and those kind of offers might not come around.

"But as we speak at this minute, I'm really unsure. I'm trying to give you an impression of being unsure.

"For me, that's what I wanted to do in 2000 when Celtic came for me. I loved Leicester City, it was great. Celtic came along and it was what I wanted to do."

Questioned as to whether or not the former Sunderland and Ipswich boss was ready for the task of managing the Scottish champions, O'Neill replied: "I think Roy's ready for anything. I think he's always been ready for anything."

In the meantime, the 62-year-old is expecting Keane to still be at his side when the Republic face Italy in a friendly at Craven Cottage on Saturday.

He said: "I certainly would be expecting him to be here for Saturday. I think that's what he wants to do as well."

Ireland also have fixtures against Costa Rica in Philadelphia and Portugal in New Jersey to come early next month.