Now, he needs that to be true. No-one around Celtic tried to downplay the significance of this match against Rennes and Sunday’s at Motherwell in the Clydesdale Bank Premier League.
It’s clear that Lennon needs victories in both of them to retain a firm grip on his job as manager. Both fixtures then need to become the catalyst for vastly improved results overall.
Last night was heartwarming for him. Celtic came from behind to deal with a capable French team and win their first match in Europe this season. Anthony Stokes’ two goals and Gary Hooper’s third were decisive.
At full time, there was a roar. A sigh of relief would have been appropriate, too. It was gutsy, winning performance which brought Lennon one step back from the cliff edge.
What Celtic showed, and what countered Rennes’ technical superiority, was the character to dig in for each other and their embattled manager. Sometimes that meant having to work hard to clean up after one of their own mistakes.
When Georgios Samaras, Victor Wanyama or Adam Matthews gave the ball away, Celtic had to hare back to chase down a flood of counterattacking opponents. Wanyama lost it one time and tracked back 30 yards to undo the damage.
Lennon had no cause to fault their effort. By the end, their finishing was also better than anything Rennes could manage.
At the start, the French simply looked like a better team. They were sharp, quick and they relentlessly tried to press Celtic in all areas of the pitch. As soon as any of the back four took possession, they had a lilac shirt all over them.
Sometimes two. In Vincent Pajot and Alexander Tettey, the French had midfielders who were threading passes through and around Celtic, constantly stretching them. Wanyama and Biram Kayal got a runaround for the first half-hour. Rennes’ big star is Yann M’Vila, the 21-year-old French international midfielder and a target for Arsenal.
Clearly, there is more to him than he showed here: M’Vila’s main contribution was bookable fouls on James Forrest and Kris Commons which earned a red card five minutes from time.
Celtic’s performance had to be viewed in the context of them being without 10 first-team players through injury, illness or ineligibility. Even so, it was startling to see Hooper on the bench, Commons still not getting a start and Glenn Loovens handed the captaincy.
There are plenty who would happily see the Dutchman hunted out of Parkhead altogether. In defence of Lennon’s decision, the team he selected wasn’t exactly overpopulated by natural leaders.
Anyway, Loovens lasted only half the game before adding himself to the list of casualties with a hamstring strain. He did not reappear after the break and 17-year-old debutant Marcus Fraser replaced him.
The seemingly irremovable flaw running through the team -- losing cheap goals -- was as evident as ever. Celtic seem to have an addiction to handicapping their own performances. The game had barely settled -- it was just 100 seconds old -- when Rennes deposited the ball in their net.
They always looked uneasy with crosses into the box and no wonder, given that the very first one was Julien Feret’s corner on to the head of Kader Mangange. Rennes’ captain powered it high into the net and a half-full Parkhead was immediately hushed.
Celtic’s gradual emergence into the game was a triumph of raw will. Although they defended well after the shock of the opening goal, Rennes were always looking to hit them hard and fast on the counterattack.
Celtic had plenty of possession in the opposition half but had little to show for it until suddenly Forrest made room for himself to unload a low shot which Benoit Costil dived to save only to inexplicably parry the ball in front of Stokes. It was a gift. The Irishman buried it for his first goal in a European competition.
His second arrived 12 minutes later, as direct and route one as you can get. Fraser Forster hoofed it up the park and Samaras won an aerial challenge to flick it on and put Stokes in behind the Rennes defence. He was cool: taking a touch before placing a low shot across Costil and inside his far post.
There was warmth from the supporters towards Commons when he came on and some appreciation, too, for the man he replaced. Paddy McCourt’s rare start was characterised by dribbles and runs which never quite amounted to much, but he was willing and committed. The same qualities applied to Kayal, Wanyama and even Samaras.
Forster contributed with decent saves to twice deny Youssouf Hadji as Rennes came back midway through the second half, but Celtic had another goal in them. Samaras picked out a delicious low cross for Hooper to take one touch and then nervelessly tuck home his finish.
The probable return of some of their absentees will give the Celtic team a different look at Motherwell. The worry for Lennon will be whether their performance and attitude will change, too. In the meantime, he is halfway towards the verdict he needs from this two-game trial.