The Scotland winger missed the recently-crowned Clydesdale Bank Premier League champions' 4-0 romp over Dundee United at the weekend with a hamstring injury.
But the 21-year-old hopes to train with his team-mates towards the end of the week as he bids for a starting slot at Hampden.
Forrest - who was today named in Scotland boss Gordon Strachan's squad for the World Cup qualifier in Croatia next month - said: "I've been feeling good. I was a wee bit tight and couldn't play on Sunday but I'm hoping to train Friday and Saturday and be fit for selection for the game on Sunday."
It has been a season of frustration for the wide man.
Forrest squeezed in 43 appearances for the Parkhead side in his breakthrough campaign last year but has been restricted to 28 run-outs, just 17 of them starts.
A nerve problem causing pain down his leg meant he was only able to muster two brief substitute appearances between the end of October and the beginning of January, while he was ruled out with the same problem for over a month following the club's Champions League last 16 exit to Juventus in March.
He returned for the 4-3 extra-time victory that saw Celtic past Dundee United in the Scottish Cup semi-finals but managed just two more games before the curtain came down on the SPL.
Now Forrest is hoping to stay injury free but admits he may have to manage his training regime carefully.
"Last season I played a lot of games and I was hoping to that again this season," he explained. "But I have not played as much as I'd have liked. Now I'm just trying to stay injury free and see how many games I can play.
"The problem has been with my hamstring but maybe coming from my back. I'm not sure. But I have been feeling better the past couple of weeks and it's the best I have felt.
"It's not been the same thing all along. It's been different niggling injuries, which has been more frustrating for me and kept me out for so long.
"I can do things in the gym to help and maybe I might not have to train some so much and just play games instead. But hopefully this is a one-off thing and this will be the only season that is affected."
With his hamstring problem behind him, Forrest is hopeful of a place in Sunday's squad as the Hoops chase a domestic double, but Lennon hasn't given his youngster any clue as to whether his wish will be granted.
"He wouldn't tell us that yet," said the player.
"This is the first time we have had a full squad to pick from but I want to be up for selection."