But, if it is to be a final fling in the Hoops on this major stage for the giant Geordie, boss Neil Lennon wants him to deliver another of his Champions League special performances.
It was Forster's spectacular saves in games against Barcelona last season, and again when the La Liga champs came to Glasgow in September, which brought him to the attention of clubs across Europe.
His form in these massive games also convinced Roy Hodgson the keeper was ready to come into his England squad, then to win his first cap.
On the back of this, Celtic are bracing themselves for big offers to come in for Forster next month, with Barcelona among the clubs linked with a move for the 25 year-old.
Lennon believes the best has yet to come from the big man, and wants him to stick around until the summer, at least.
But if this is going to be his last Champions League appearance for the Hoops - already destined to finish last in Group H - Lennon would like to see him achieve his first shut-out in the group.
He said: "Forster would be a great keeper for any team. It's interesting he's linked to teams like Barca - but I hope he stays at Celtic."
Lennon knows it will require more than Forster to be on the top of his game tonight if they are to add to the three points they have taken in the competition.
And the Hoops boss added: "Getting a good result against Barca is important in terms of the context of the season and also looking ahead to the next one."
Lennon is pleased to have Scott Brown and Nir Biton available again after suspension, but is pondering who will step in for the banned Emilio Izaguirre, with Adam Matthews a strong candidate.
But having been out since October 5 with a broken collar bone, starting the Welshman might represent a gamble, and either Charlie Mulgrew or Joe Ledley could step in.