Neil Lennon has first refusal on Forster, but the goalie is in no rush to open talks with the Hoops boss and admits he wants to wait until the end of the season when he's in a position of strength.
Forster, 23, told the Scottish Sun: "I'm on loan here until the end of the season and Celtic have first option to sign me.
"But I'm happy leaving it until the summer.
"I'd rather just concentrate on football and we can sit down and sort everything else out in the summer.
"If you are playing well it helps. It strengthens your position in negotiations.
"But it's important to play well and focus on the football and, most importantly, win the league."