England goalkeeper Fraser Forster does not know if he will still be at Celtic when they next play in Europe.
Norwich captain Sebastien Bassong has signed a new two-and-a-half-year contract.
Millwall have signed Lee Martin on a free transfer from Ipswich.
The 26-year-old winger, released by the Tractor Boys at the end of last month, is new Lions boss Steve Lomas' third signing of the summer following Stephen Bywater and Steve Morison.
Martin began his career at Manchester United and had spells on loan with Royal Antwerp, Rangers and Stoke.
He joined Ipswich in 2009 and went on to make 100 appearances for the Suffolk outfit, scoring six goals.
Meanwhile, the Lions have confirmed midfielder Liam Trotter will miss the start of the season after undergoing knee surgery.