Johan Mjallby has confirmed that midfielder Ki Sung-yueng wants to leave Celtic.
The South Korean, 23, has not returned from playing for his country at the Olympics amid speculation Barclays Premier League side Swansea are poised to launch a £6million bid.
"He is keen to move on and the club is in discussion with another club so we have to wait and see what happens. I can't say who the clubs is," Celtic assistant manager Mjallby said
"There have been a few clubs interested in him but I know for sure there has been one bid for him and I think maybe one or two other bids.
"He is a quality player but on the other hand he is keen to move on so the club needs to do something."
Asked whether a replacement would be sought were Ki to leave, Mjallby said: "He has not really been a part of the season so far so we have shown that we can live without him, but on the other hand it would be nice to get someone else in if he goes away.
"If quality players leave the club, you want to freshen things up and have competition."
Celtic boss Neil Lennon had 10 players missing for the 1-1 draw with Ross County on Saturday, with injuries sidelining Dylan McGeouch (broken jaw), Daryl Murphy, Gary Hooper (both hamstring), Anthony Stokes, Filip Twardzik (both ankle), Mo Bangura (thigh), Rabiu Ibrahim, Paddy McCourt, James Forrest (all groin) and Scott Brown (hip).
The Irishman had hoped Brown, McCourt, Hooper and Forrest would all be fit for the Champions League play-off against Helsingborg on Tuesday and Mjallby believes they are winning that battle.
He said: "We have Scott Brown, James Forrest, Paddy McCourt and Gary Hooper all travelling. We are going to train later on at the stadium and see how they are."