Aitchison, at 16 years and 71 days, became the youngest player in Celtic history to both make his debut and score a goal.
The teenager featured in the Scottish Premiership match between the Bhoys and Motherwell at Celtic Park on Sunday afternoon.
The youngster came on as a substitute in the 75th minute and scored just two minutes later, as the Hoops ended a successful league campaign with a 7-0 hammering of Motherwell.
Christie, who was also among the goals on Sunday and is just 21 years of age, believes that Aitchison has a bright future.
"I think it was his first touch as soon as he came on and I think every player in that changing room was delighted for the wee man," Christie told The Glasgow Evening Times about Aitchison. "I’ve played a few under-20s games with him and he has really impressed me.
"I couldn’t believe how young he was when somebody told me. So he has a giant future ahead of him if he keeps his heads down."
Celtic did not have a great season, although they won the league title for the fifth season in a row. Ronny Deila is leaving as the manager, and a replacement has yet to be named.
The Hoops do have a good squad, but some of the players have underperformed this season and need to step up their game.