Ivica Olic looks to be on his way back to Hamburg, with Andre Schurrle increasingly likely to join Wolfsburg.
Sunderland have secured a loan deal to take midfielder Ki Sung-yueng from Swansea for the rest of the season.
The 24-year-old South Korean international becomes the Black Cats' 11th signing.
Ki, who will join up with international team-mate Ji Dong-won at the Stadium of Light, has been allowed to leave the Welsh club despite making 38 appearances last term.
Ki first arrived in Britain back in 2009 when he left FC Seoul for Celtic - impressing in Scotland's top flight and prompting Swansea to fork out around £6m for his services last summer.