Last season was spent accumulating plaudits but James Forrest has mostly gathered only frustrations in this campaign.

The attacker has had to endure a series of injuries that have interrupted his involvement, and forced him to change aspects of his lifestyle as well as his training regime. "I changed my car," he said, "I've tried everything."

Some of Forrest's problems are a consequence of his speed. Like other quick players, he has to manage carefully the stresses and strains on his hamstrings and back. Nerve problems have also beset the 21-year-old, although his most recent complaint was a bulge in a disc in his spine. That was treated with an injection by doctors in London and he was fit enough to play a pivotal role in Celtic's 4-3 victory over Dundee United in last Sunday's William Hill Scottish Cup semi-final.

Afterwards, Neil Lennon described Forrest as "a brilliant player". The Celtic manager has always been a great admirer of the player, for his pace, attacking instincts and ability to create alarm in opposition defences. Lennon even went so far as to tell the press last Friday that Forrest would not be fit for the semi-final so that United would be caught unawares. Even so, this has been a gruelling campaign for Forrest, who has made 26 appearances, although many have been from the bench.

"It's been hard," he admits. "I've come back a couple of times and then played a few games and got injured again. A lot of fast players seem to get more injuries than players that are not so quick. I am just going to have to do my stuff in the gym and stay injury-free for as long as I can. I've had nerve problems and getting pains from my back going down my legs. It has been niggling away. It's nothing major but it has been on and off since October. They said that once I get rid of it, that should be me fine for a long time. [Doctors] think that maybe because I played a lot of games last season it took its toll."

There are no long-term issues for Forrest although he will have to ensure he works on specific muscle groups in the gym and sticks to specific physio routines. Changing his car was to ensure the driving position did not place additional strain on his back, hamstrings and calves. Andy Murray has suffered similar problems with his back, and part of his coping strategy has been to stop playing five-a-side football.

Forrest is essentially an optimistic figure and his rehabilitation periods were generally in the company of team-mates, including the captain Scott Brown. He missed significant matches this season but there is the consolation of being part of another league-winning side – Celtic need one more point to clinch the title and could win it on Friday night if Motherwell fail to defeat Dundee United – as well as the prospect of the Scottish Cup final against Hibernian.

"I've had my rest. I'm raring to go now," Forrest said. "I'm just a bit gutted there's only five or six games left. The double is still a big deal for us. Celtic have not done it for six years now, so that would be a big achievement."