Neil Lennon aware Old Firm clash is effectively part two of his job interview

His six-and-a-half years contesting the fixture brought sequences of utter command, afternoons of chaos and bucketloads of controversy. In these the midfielder's rage, religion and red blooming hair, even, proved triggers for national and cultural debate. Yet, contextually, Tuesday evening's hosting of Rangers is a whole new ball game for Celtic's interim manager. Boil it right down and the encounter means pretty much nothing to everyone else... and absolutely everything to him. It is, effectively, the second part of a job interview after the first part, the Scottish Cup semi-final against Ross County, proved one of those anything-that-could-go-wrong-did experiences. Lennon doesn't attempt to side-step what could be riding on the outcome in two days' time.

"Old Firm games define you and everybody is looking into this one," he says. "I think it is a bit unfair really, to say that if I win the game I get the job and if I don't I will not get the job. I think I should be judged over the piece really, not just over one game. But that is the situation I am in, and I accept that."

It is generally accepted that the Celtic board are looking for a reason/excuse – delete as you feel appropriate – to give Lennon the job. A resounding victory, even against already-crowned champions, could swing it. Any sort of defeat surely would spell the end for Lennon's prospects of landing his present post permanently. Yet, Lennon is too centred, too perceptive, to do other than swat away any talk of victory boosting his club for next season. He can look beyond his own horizons. "Listen, August is a long, long way away. It is just all about winning the game, whether it gives them confidence or not for next season. It is to give the fans something. It is just about beating Rangers at the end of it, no matter what the game is or what the occasion is."

The occasion could be a valedictory one for many in the Celtic ranks. There seems a suggestion Lennon could field a young side for the league-closing encounter away to Hearts next Sunday. At least that is what can be gleaned from his comments that he'd like to think his players will "put on a show" in a "cup final sort of atmosphere" because for "a lot of the players it will be their last game of the season; possibly last game of the club".

Robbie Keane is heading into week zero of his Celtic career. Lee Naylor won't be signing a new contract, Edson Braafheid has been a loan failure, while doubts remain over whether Landry Nguemo and Diomansy Kamara will earn permanent deals. Lennon is understood to want to move on Georgios Samaras and Marc-Antoine Fortune. Aiden McGeady, Andreas Hinkel and Artur Boruc are sellable assets it is believed the club could look to cash in to provide a sizeable summer transfer budget. Add to that the fact fringe players Zheng Zhi, Darren O'Dea and Mark Wilson appear to have little future, and the turnover could be even more rapid in the next few months than the past year.

For Lennon, an Old Firm encounter proved the beginning, not the end, for him at the club. Even when it wasn't one he even played in. Celtic proved so soft through the middle in losing 5-1 away to Rangers in late November 2001 – after Alan Thompson had been red-carded – that then manager Martin O'Neill told his board in no uncertain times they had to deliver him the fellow Irishman who had become his midfield metronome at Leicester. They did so within two weeks, successfully ending their pursuit of a man they thought they had bagged six months earlier.

"Paul Lambert had broken his shin at the time so it was really lucky for me the transfer came around," he said. "I thought I had missed out on it the previous summer when Leicester wouldn't let me go, but the opportunity came up and I really enjoyed it."

Incredibly, he never missed a single Old Firm match in his entire time in Glasgow, his record reading 18 wins, five draws and ten defeats. "I'm surprised I lost ten," he says. "I won my first five". The first was a "tasty" League Cup semi-final Celtic scored a 3-1 success in and which brought three red cards. "It was a blur. I don't think anything prepares you for the first one."

Lennon's favourite was the 1-0 win in May 2004 earned by "Sutty's (Chris Sutton's] chip in the last minute of the whitewash season". Celtic's first campaign clean sweep against Rangers since 1971-72, it was the sixth in an unprecedented seven-game sequence of derby victories for the club. Lennon enjoyed more league wins at Ibrox than Rangers manager Paul le Guen and recognises the power of passion-fuelled, petty, parochial and, often, pathetic spectacle. "In my experience, Old Firm games define you, and they define your reputation. The Old Firm fans will always hark back to them: 'Do you remember that game?' or whatever."

Lennon will never be allowed to forget being grabbed by O'Neill and marched up to salute the Celtic support at the end of a 2-0 defeat at Ibrox in November 2004. The Celtic manager later condemned the virulent "racial and sectarian" abuse meted out to the player at that ground. Ten months later, Lennon had to be restrained when it looked as if he was going to dish out some physical punishment to referee Stuart Dougal at the end of the 3-1 loss. Gordon Strachan's introduction to the derby as manager ended with Lennon copping a post-final whistle red card; his second in these highly combustible confrontations.

"The Dougal thing, obviously looking back on it I regret it. Not totally, but I regret it," Lennon says. "And the day Martin came out on to the pitch he was just basically saying that he had had enough of listening to what I had to go through. But again, I thrived on that. I loved being public enemy No.1, and that made winning the games that bit sweeter, if it can get any sweeter. But every one that you win you relish and every one that you lose hurts for a long, long time."

If it all goes horribly wrong on Tuesday, Lennon could be hurting for the rest of his days.