Stokes made his first appearance in the Champions League proper against AC Milan in midweek and has at last moved into position to be Celtic's first-choice striker. But Lennon considered letting Stokes go at the end of last season after feeling repeatedly let down by the 25-year-old Irishman.
Both Lennon and chief executive Peter Lawwell told Stokes that he had tarnished the club's reputation last season by attending a memorial event in Dublin for murdered Real IRA commander Alan Ryan. But what really jeopardised Stokes's Celtic career was a number of off-field disciplinary matters concerning his discipline and professionalism.
When asked if Stokes could have been on his way out, Lennon said yesterday: "Yes, I had him in the office a couple of times. It's fair to say he was walking on very thin ice. It wasn't about tarnishing the club, he was hurting himself. It was nothing to do with stuff last year, the stuff in Dublin, it was just his indiscipline around the training ground and the team. He's tidied that up now and become a really good professional."
Injuries also contributed to Stokes not playing a single minute against Barcelona, Benfica or Spartak Moscow in last season's Champions League group stage and Lennon believes that sobering experience made Stokes realise his attitude had to change.
"I don't know what made the penny drop for him. Maybe the injury and missing out on the whole Champions League campaign last year, sitting in the stand and watching the boys play in wins against Barcelona and Spartak Moscow and realising what he has at Celtic. Sometimes you don't know what you've got until you're not there. I've never spoken to him about it but I certainly think the natural thing would be to sit down and think 'I want to be a part of this', and now he is."
Talks over a new contract have stalled after Stokes turned down the club's initial offer, but it remains likely that a new deal will be settled and announced within weeks.
"I had question marks over his temperament in big games but his athleticism and fitness has improved and certainly his football," said Lennon. "His movement as a striker was always good and he had adaptable feet, but he was curtailing his own progress with indiscretions and ill-discipline. Since he's come back from injury he's knuckled down and is doing his talent justice now.
"He did a lot of upper body work when he was out but he is a naturally strong boy. In the strength tests that the boys do at the start of the season he's top of the list, the weightlifting and that sort of stuff. He doesn't look it, when you strip him off he's just a naturally strong boy. There were things he was doing in the game on Wednesday, he was challenging for balls in the air whereas before he was a little bit wishy-washy. I think with the fact Gary's [Hooper] gone he's looking to be the No.1 here and he's enjoying that challenge.
"I'm really liking what I'm seeing in him at the moment. He's always had goals in him and he will score goals at Champions League level if we can get the right service to him. As a lone striker you sometimes have to create your own opportunities but the one he had in the first half in Milan he's latched on to a mistake and I fancied him to score, but he just sclaffed the shot a little bit. And if his free-kick had been an inch or two lower, instead of hitting the bar, we'd all be raving about him."
Celtic return to SPFL Premiership duty against St Johnstone at Celtic Park this afternoon.