On Saturday night, at Craven Cottage, Ireland gave their best performance since Martin O'Neill became the manager. They grew into the game after a slow start, and they would have won if Stephen Quinn hadn't John Sheridaned a late chance against the Italian crossbar.

Wes Hoolahan, Jeff Hendrick and Anthony Pilkington stood out but almost every player emerged with some degree of credit, so it was a pity that on a night when he could have been saying a lot of nice things about his players, O'Neill mainly answered questions about his assistant.

It's been that way since his first press conference last November. O'Neill may have begun to realise on that day what he surely knows now: he could have appointed Bill Clinton as assistant manager and it would have been less of a talking point.

While there has been no outward sign of friction in the O’Neill-Keane relationship, it’s obviously rather unusual for the assistant to command a higher public profile than the manager.

The fascination has always been the question of how Keane, a dominant personality who is accustomed to getting his own way, would adapt to a subordinate role.

Séamus Coleman referred, after the Turkey game, to "the two new managers" but O'Neill has always been clear that only one of the managers is making the decisions.

Final say

The week before last, when the rumours linking Keane and

Celtic

began, O’Neill explained that, while he often sought his assistant’s view on team affairs, Keane’s input “would not necessarily change my opinion”. He added that “in the dressing-room, at half time say, I’m the one who speaks.”

Last Thursday, at the open training session, Keane stood beside one of the goals at the Aviva and watched as Steve Guppy put some of the players through a shooting drill.

He was scheduled to speak to the media afterwards but O'Neill turned up to confirm that Dermot Desmond had been in touch regarding the possibility of Keane joining Celtic.

The following day, John O'Shea would joke that if Keane really was about to leave then the decision to bring in Guppy and Steve Walford looked a prescient move by O'Neill.

O’Neill denied he had invited these trusted former lieutenants to join as insurance against the departure of Keane, or that their arrival effectively rendered Keane redundant. “They have come in because we have a number of games in quick succession,” he said. “Roy’s role has nothing whatsoever to do with that. Roy’s role has not been diminished.”

But since O’Neill has the final say on tactics and selection, since he is the sole voice of authority in the dressing room, and since he is plainly well-covered for coaching staff, it’s not easy to discern the areas where Keane can really pitch in and make a difference.

The media interest in everything he has to say gives him public influence, but he has to tread carefully, since there is always the risk of appearing to undermine O’Neill if he strays off-message.

You could see how he might be tempted by the offer of a position with real decision-making power.

Ever since O’Neill confirmed that he’d taken the call from Desmond, there has been a sense of inevitability about Keane joining Celtic: if it wasn’t going to happen, why would they have gone public? Before Keane accepts the offer, however, he should remember why Celtic are looking for a manager in the first place.

Neil Lennon had just won his third successive league title. He was popular with supporters, he liked living in Glasgow, and had always described it as a privilege to be the Celtic manager. So why did he walk?

Everyone knows that the meltdown of Rangers has turned the Scottish Premier League into a competitive non-event. Lennon could have lived with that. There was always the Champions League. Unfortunately, Celtic's squad is probably not strong enough to qualify for the group stage, because the board made a habit of selling important players like Victor Wanyama and Gary Hooper without investing in adequate replacements. Lennon argued against that.

Intolerable

Last month,

Georgios Samaras

was released by Celtic after his contract expired. He said Lennon “ would have loved me to stay. But me and the gaffer don’t make the decisions. People above us make the decisions.”

Working under these conditions eventually proved intolerable for Lennon. Would it be any more appealing to Keane? He chafed against budgetrestrictions at Sunderland, but compared to Celtic, Sunderland are Manchester City.

On Saturday, O’Neill said he expects a decision by Wednesday. He insisted he would be disappointed to see Keane go. You felt sure that O’Neill would find the strength to pick himself up and carry on. Whatever happens, he’ll still be calling the shots. For his assistant, the future is not so clear.