Scotland's kids kick off their Uefa Elite group tonight at Burton Albion's Pirelli Stadium when they face Ukraine.
Henderson will be a key player for the Scots after he made a real impression this season with ex-Hoops manager Lennon.
The 18-year-old went on to make eight appearances for the SPFL Premiership champions this season.
Henderson said: "The manager gave me the opportunity in Germany [on pre-season] and I think I took it.
"The manager felt he could trust me and that was great from my point of view.
"He was brilliant for me. I trusted him 100%. 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.
"Last summer, I was moving from Barrowfield to Lennoxtown, hoping to be involved in the development squad and the Under-20s, but then I got the call to go away with the team for pre-season.
"It's just carried on from there."