Celtic 'have already interviewed' Robbie Keane as Martin O'Neill sack decision looms

Robbie Keane is being lined up as an immediate replacement for Martin O'Neill as Celtic prepare to pull the trigger on their boss.

The 74-year-old is under pressure at Parkhead following a disastrous week of fixtures, with two defeats in the Old Firm derby against Rangers and a Europa League loss to Ferencvaros.

Should Celtic decide to part ways with O'Neill, or if he decides to leave the club, then Keane is considered his most likely replacement as he has been on the club's radar long term.

Former Man United chief scout Mick Brown told Football Insider that appointing Keane would be an easy decision for Celtic after the work was done in the summer.

The former Ireland international was interviewed by the Hoops as they made a decision about their permanent successor, before they opted to continue with O'Neill.

As a result, they already know what Keane has planned for the club and how he would operate, and could turn back to that data as they aim to land their next boss.

Could Celtic move to appoint Robbie Keane?

Football Insider revealed in May that Keane was high on Celtic's list of managerial targets after he left his position as the manager of Hungarian outfit Ferencvaros.

At the time, O'Neill was seen as the preferred candidate and ultimately landed the full-time job, but discussions were held with Keane as a leading target.

Those discussions have now opened the door for him to take over should they pull the trigger on O'Neill, with doubts about the current boss' long-term future growing.

"If Celtic are going to part ways with O'Neill then they will want a replacement in quickly," Brown told Football Insider.

"It's not quite as easy as that, we saw that last season and that put them in a very difficult position, it's the reason they've ended up with O'Neill staying for another season.

"But when you look at the options available to them, it's safe to say Robbie Keane is the most likely candidate because they've already interviewed him.

"They'll know what he's about, what his ideas for the squad are, his style of play, how he works on the training ground, all of that sort of thing.

"So it would minimise the amount of time they have to spend looking for somebody, because all of that information from his last interview will still be available to them.

"When you're looking at all of the options, he probably is the one that makes the most sense, unless they think there's somebody else who could be persuaded."

What is the latest on Martin O'Neill's future?

Speculation about potential long-term managerial candidates at Celtic have come as they contemplate O'Neill's future with pressure on the boss becoming unbarable.

Celtic suffered a 1-0 defeat at home against their Old Firm rivals on 20 September, which sparked chants against the manager from the supporters at Parkhead.

As a result, Brown told Football Insider that O'Neill could walk away from his position as manager, and he later confessed that he would consider his future during the international break.

Since taking charge on an interim basis last season, the manager has done a good job at Parkhead, and led his side to Scottish Premiership and Scottish Cup success.

However, his team have not performed in their biggest games this season, leading to increasing frustrations, and O'Neill is unlikely to stick around when he is not wanted.