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.
CSKA Moscow have completed the signing of Rasmus Elm from AZ Alkmaar, the Dutch club have confirmed.
The 24-year-old Sweden international has signed a contract until 2015 for an undisclosed fee.
Elm spent three years in Holland, making 83 league appearances after signing from home town club Kalmar.