Celtic boss Tony Mowbray has admitted he is "in the market for quality footballers" following Sunday's Old Firm derby stalemate.
The Hoops failed to close the seven-point gap to leaders Rangers after Scott McDonald's 79th minute opener at Celtic Park was cancelled out by Lee McCulloch.
They had earlier seen a first-half effort from Marc-Antoine Fortune ruled out in controversial circumstances.
"I am in the market for quality footballers," said Mowbray. "The board are fully aware of the situation.
"There are a lot of conversations going on at the moment with various clubs, either to sell players or to buy players."
However, Mowbray has denied suggestions that soon to be out-of-contract defender Gary Caldwell will definitely move on this month.
"I don't know if it was Gary Caldwell's last game in a Celtic jersey," he said following reports of an imminent move to Middlesbrough, where he would link up with former Bhoys boss Gordon Strachan.
"We are all very aware of his contract situation and if there are conversations to be had, we will have them.
"What I do know is that we will be in control of whether Gary stays or goes.
"He is our player, he is under contract and we will decide what is best for this football club, first and foremost."