Celtic manager Neil Lennon is delighted to have the "unique presence" of Fraser Forster at his disposal again.
Lennon brought in Forster on a season-long loan from Southampton after discovering Scott Bain was facing four-to-six weeks out with a dislocated thumb.
Craig Gordon comfortably kept a clean sheet in Celtic's 2-0 Europa League play-off win over AIK on Thursday night but the Scotland goalkeeper now faces a fight to keep his place for Sunday's visit of Hearts.
Lennon said: "We were a goalkeeper down and the opportunity came about to get Fraser back. I am delighted we have acquired his services.
"He is an outstanding goalkeeper so I have three outstanding goalkeepers now and it's a department that is very important. We have strong competition and that's what I want.
"He has missed out on a little bit of football in the last year or so but we know of his talent. He had an outstanding time here, he is a Premier League goalkeeper and is itching to play.
"He gives you that presence in goal which is unique. He was outstanding for me the first time and I hope he replicates that the second time."
Gordon did not have much to do as Celtic kept a clean sheet with new signing Christopher Jullien at the heart of their defence.
The £7million summer signing from Toulouse got a taste of the pressures of playing for Celtic over the past week with the fallout over their Champions League exit continuing but he welcomed the challenge after the game.
Jullien, who was not involved in the costly home defeat by Cluj, said: "I knew Celtic was a big, big team, I knew it before. It's a big club, there is a lot of expectation and when I signed I knew what I was coming into.
"It's good for my career and it's a really good challenge.
"It was really important to keep a clean sheet at home and we did. We need that European challenge and I have trust in the team."
Another Frenchman, Odsonne Edouard, hit the second from a free-kick and Jullien believes the striker can go all the way to the top after witnessing the 21-year-old's improvement from his days on loan at Toulouse from Paris St Germain.
"I have known Odsonne a long time since I played with him in France," the centre-back said. "He is just unbelievable.
"The way I saw him in his first year of professional football in Toulouse and now seeing the player he is, is just remarkable.
"I don't think there is any limit. He has a lot of quality. He can head, keep the ball, pass, score, dribble. For me, he can do everything.
"I hope he is still going to work on his game but since I knew him he has been on his way to the top."
