When Martin O'Neill replaced Brendan Rodgers in October, the Celtic ship was listing. When he returned for a second interim spell after Wilfried Nancy's tumultuous and brief reign, the ship was taking on water at an alarming rate.

Celtic have needed a safe pair of hands and a figurehead to unite a fanbase in revolt twice this season. On both occasions they have turned to O'Neill to save them. He has lost just once in 14 matches across all competitions, a 3-1 reverse against an impressive Midtjylland outfit.

O'Neill has facilitated Celtic clawing their way back into the Scottish Premiership title race and Thursday's win over Utrecht keeps their European campaign going, with a knockout play-off tie against either Stuttgart or Ferencvaros to come after Friday's draw (12:00 GMT).

He has reversed Celtic's on-field fortunes while evidently enjoying the off-field side of the job, joking his way through news conferences and playing the showman role he always has. The last time Celtic won a two-legged European tie after Christmas was back in 2004 under - you guessed it - O'Neill, when they stunned Barcelona 1-0 on aggregate in the Uefa Cup.

If the two-time interim boss is to replicate that feat 22 years on, he was candid about how he needs additions in the remaining few days of the window. In his post-match news conference, the 73-year-old was asked specifically about links to two wingers - Frosinone's Fares Ghedjemis and Dunajska Streda's Damir Redzic - that surfaced before the Utrecht game.

You could almost hear the sparkle in his eye when he answered. "You wouldn't be a million miles off," O'Neill said. "That I don't know [about a percentage]. It could be [one rather than both]. I don't think we're in a position [to do both], yeah. There's progress today on certain things. I don't want to be cryptic, but I would hate to say something was certain and it fell away.

He had the assembled media pack giggling away as he told certain newspaper journalists he had been seeing their faces in his sleep, such is the interest around potential transfers at Parkhead. And it is not only the media he has charmed, but his players, too.

Where they were finding ways to lose under Nancy - and Rodgers to a lesser degree - Celtic's much-maligned squad are now grinding out results, albeit the 10-man reigning Premiership champions could not beat current leaders Hearts at the weekend.

Nevertheless, the upturn in performances and results since Nancy's calamitous tenure has been stark, and that is without key starters Alistair Johnston, Cameron Carter-Vickers and Jota.

Midfielder Benjamin Nygren, who scored his 14th goal of the season against Utrecht, was asked about the impact O'Neill has had. "He's making a big difference," the Sweden international said. "He knows the club, he's been here. He knows how it works here and he's loved by everyone around the club.

I think he brought in a lot of confidence, so we've been a lot better since he came back." There are storylines wherever you look with O'Neill, such is his history with Celtic and the esteem in which he is held by fellow managers and both former and current players.

He could be up against a man he managed for several years at international level if Robbie Keane's Ferencvaros are the play-off opposition. "You always want to play against very, very experienced managers," former Celtic striker Keane said after his side were beaten 4-0 by Nottingham Forest on Thursday.

"I've done it twice in this campaign, with Rafa Benitez, and then with Sean Dyche, who has got wealth of experience. There aren't many more experienced than Martin, and what he's done in the game and what he's done since he's come back to Celtic, because he's given a lot of energy to the club, of course, a lot of energy to the players, with a club that was obviously very, very down. That's what Martin does. So maybe it's written in the stars, myself against Martin. I don't know. But again, regardless of who we play in the two games, it will be so difficult."