Colby Donovan says he is determined to kick on after signing a new five-year contract with Celtic.

The 20-year-old defender had less than two years of his existing deal to run, but a lengthy extension is reward for his excellent form of late.

The Celtic academy product, who turned professional in 2022 and made his full debut three years later, has been a capable deputy for the injured Alistair Johnston.

Having racked up 28 appearances in all competitions last term, the right-back has grown in stature this season and been called into the full Scotland squad.

When the new deal was announced yesterday, Donovan said he was ‘over the moon’ to have committed himself to the Parkhead club until 2031.

‘As a young boy coming through at Celtic, you strive to be a first-team player, and to think where I am now and where I was a year ago today, it’s been a rollercoaster.

‘I’ve loved every single minute, but it doesn’t stop now. I’m just going to keep kicking on.’

Acknowledging that it had not been easy to achieve first-team football at a club like Celtic, Donovan added that he always believed in his ability.

‘You’ve got to have that belief as a young player coming through here at Celtic. You see all the signings that they bring in and it’s a top club. They expect to win every single week.

‘So as a young player, it’s tough, but you always need to believe, and I know for certain when I was a kid, I knew I could come through and do it.’

Donovan’s deal comes as Celtic fans await news of the latest injury fears surrounding Johnston. The Canada international missed most of last season with hamstring issues and suffered a recurrence of that problem in August.

He made his long-awaited comeback in the 2-1 win at Easter Road on Sunday, only to last just 21 minutes, prompting new concerns about his ongoing fitness.

It is a worry for Martin O’Neill, who can at least be encouraged by the progress of Johnston’s deputy. The Celtic boss described Donovan’s new deal as ‘fantastic news’ for the club.

‘Although still a very young player, he has shown such maturity, strength, and resilience,’ said O’Neill. ‘In fact, he has been exceptional for us.

‘He has come in when we needed him, given everything for our cause, and shown what a quality player he is.

‘He is a young man with a tremendous attitude and with a recent international call-up as well, he has had a phenomenal few months. I am so pleased that he sees his long-term future at Celtic.’