Celtic breakthrough star Colby Donovan has vowed his determination will not be dimmed by the comfort of an extended contract.

The right-back this week signed an extension which committed his future to Celtic until the summer of 2031 after making 44 first-team appearances.

The first person the 20-year-old told about his new contract was fellow full-back and Celtic fan Kieran Tierney.

"He was a big role model for the boys in the academy when I was younger growing up," said Donovan.

"Now I'm playing with him and I'm a good mate with him as well, so it's mad. But there's no better person to look up to than KT. I'm loving learning from him every day and he's at the top of his game.

"When I was younger, it was just his determination to give everything for the badge, so that's what I see in his game even now as well, he gives everything for the club.

"So that's what I try to put into my game. You might not be having the best of days but you just need to give everything for the club and for the boys, don't you?"

Donovan's interactions with Tierney and other team-mates including James Forrest and Callum McGregor began in his school days.

"I remember I actually got a photo of KT, I'll need to find it somewhere, but I was telling him about that the other day," he said.

"And you had Cal, James, sometimes they'd come down to Barrowfield and talk to the young players and that was such a good thing for the young players, seeing that it is possible to come through at a big club like this.

"When you see them doing it and, obviously I'm doing all right for myself just now, I just hope the academy players are looking up to me as well."

Another hamstring injury for Alistair Johnston means Donovan is likely to start regularly until the international break, when he hopes to be in the Scotland squad again.

But his obvious enthusiasm for playing for Celtic makes it highly unlikely he will take his first-team place for granted.

"You know how hard it is to come through as a young player," he said. "Sometimes you'll get your opportunity and maybe it'll never happen again.

"It's about taking that chance and not looking back and that's what I've been doing. I'm still doing that now. You're never destined a place at Celtic.

"It's such a big club, you're expected to win every game so I just try and do everything that I can for the club and for my team-mates and hopefully put on a good performance."