The 18-year-old was at first invited on the club's pre-season tour of Germany and went on to play in eight competitive games for the champions.
The midfielder's campaign has since been extended to comprise matches with Scotland Under-19s. He is expected to feature prominently for a side which begin their UEFA Elite group campaign against Ukraine tonight, with the match to be held at Burton Albion's Pirelli Stadium.
That meant Henderson was absent when Lennon announced his decision to step down as the club's manager. However, the teenager has been quick to acknowledge the impact the coach made on his nascent career.
"The manager gave me the opportunity in Germany and I took it," said Henderson, whose Scotland team also face games with England and Montengro. "The manager felt he could trust me and that was great from my point of view. He was brilliant for me. He was always giving me tips in training about how to improve my game so I'm very grateful to him.
"He expected me to play the same way as the boys who have played in the Champions League campaign. I just tried to play the way he wanted me to play to keep him happy. It's been a brilliant season. It's been a great experience for me and I'm just hoping to build on it for next season."
It is a sentiment shared by many of the players in this Scottish Under-19 squad, not least prodigious Dundee United pair Ryan Gauld and John Souttar. Those players had been the subject of much discussion between Ricky Sbragia, the Under-19s coach, and his Under-21 counterpart Billy Stark as they debated which squad they would be involved in.
The decision has been taken to utilise the talented youngsters in the Elite tournament rather than in the Under-21s' European Championship qualifier against the Netherlands next week and Sbragia is delighted to have them available.
"We spoke about it over the last six to eight weeks and we agreed if Billy felt he needed them for the Under-21s then that was okay. We would just work round that," said Sbragia.
"They are there to be developed. If they are in the 21s then we have done some part of our job right. We spoke on the first night about a good team spirit and togetherness and that's really important. Gauldy and Souttar have the experience in the Euros too."