Celtic manager Neil Lennon spoke to Norwich boss Paul Lambert, where Forster has previously been on loan, to ask about the stopper.
He will put pressure on current first choice Lukasz Zaluska, and there must be an opportunity of a run in the side, because Forster insisted he was going out on loan "for first team football ... I don't want to spend the season sat on the bench".
Lennon: “He’s a big boy, he’s come highly recommended.
“I’ve watched him myself a couple of times.
“His age, 22, is the only thing going against him because otherwise he’s all the qualities you look for in a goalkeeper.
“He’s got a massive presence and he’s come highly recommended from people in the game whose opinion I trust, so if the medical goes okay, we’ll take him on board.
“We’ve needed competition in that area so he’ll add to that.”