Celtic boss Ronny Deila says keeping his best players will take priority over acquisitions in the transfer window.
Chelsea striker Fernando Torres is understood to be set for a return to Atletico Madrid, according to Sky sources.
Lille star Eden Hazard has confirmed he will be playing in Manchester next season, but refused to reveal whether it will be at City or United.
The Belgium international's future has been the subject of intense speculation for some time with a host of clubs across Europe chasing his signature.
Hazard revealed over the weekend he would be quitting Lille at the end of the season after six years at the club and has been strongly linked with both City and United, though the former are reported to be in pole position to sign him.
The 21-year-old has now confirmed he will be moving to the Premier League and will be plying his trade in Manchester next season after being named Ligue 1's Player of the year for the second consecutive season.
Speaking at the awards gala and when asked about his likely destination at the end of the current season, Hazard said: "To Manchester, I've already said. The decision will be taken soon."