The tournament is for under-19 players, but the Celtic manager has carefully followed the progress of his club's youth academy graduates. He attended all of the home fixtures last season, and subsequently promoted several members of the side into the first team.
Games against Marseille, Barcelona and Manchester City provided an insight into the merits of Celtic's youth department. Individuals were assessed, too. Paul George, Lewis Toshney, Marcus Fraser, Dylan McGeouch, Filip Twarzik, Tony Watt and Jackson Irvine all played in the NextGen Series last season and made the step up.
The competition has been devised as a tournament for Europe's elite young players, and is constructed along similar lines to the Champions League. Games are played at recognised stadiums, in front of crowds, and when teams travel away they train on the pitch the night before, as is customary for senior sides. There is worth in the players becoming used to the routine, but it is the competitive challenge of facing new players and new tactical systems that is most rewarding.
Celtic begin their involvement in this season's competition tonight, with the visit of Sporting Lisbon, with Aston Villa and PSV Eindhoven also in their group. The game will be at Firhill, since the Celtic Park pitch will be used heavily this season with the first team being involved in the other Champions League. It is a chance for young players to persuade Lennon and his coaching staff they are ready to move up to the next level.
"We hope to see the same benefits that we did last season," said John Kennedy, who manages the side. "It's another step in their development. There's a huge learning curve for both the players and the staff when it comes to European fixtures. When you are playing against top opposition, you see the best of your players. We need to keep pushing them and pushing them."
Kennedy is reluctant to dwell on his own experiences. There is an element of modesty in his reticence, but also a natural wish not to keep looking back, since the past includes the injury which ended his career prematurely.
He was pitched into a Champions League game at Camp Nou against Barcelona without the benefit of the kind of experience gained in the NextGen Series. He thrived, and his display remains vivid in the memory, but he recognises the worth of being better prepared.
"As a young player, I'd have loved to have had this experience," he said. "Our players should look upon this as a big opportunity to push themselves on and see how react against some of the best young players around.
"If the manager sees that they're good enough, he'll bring them in and give them an opportunity. It's all about developing players to play in the first team and become Champions League players."
Irvine made his competitive debut for Celtic last Saturday, coming on as a half-time substitute against Hibernian. Tall and mobile, he has been comfortable at centre-back and in midfield for the youth sides, although he was less imposing against first-team players last weekend. The experiences he accumulates will enable him to become more streetwise, but he is already a strong-willed individual.
He was born in Australia, but his dad was originally from Aberdeen, which allowed Jackson to represent Scotland at youth level after he moved to Glasgow from Melbourne to sign for Celtic. He has since switched his allegiance back to Australia, though, and is clear-minded about his choice. "It was a hard decision, but there was a bit of a mix-up as people thought I was born in Aberdeen, but that was my father," he said.
"I grew up wanting to play for Australia. I've always been proud of my Scottish roots and to get picked to play for the country was a huge honour. I don't regret playing that U19 game for Scotland but when it came down to it, I want to play for the Socceroos."