Bundesliga strugglers Borussia Dortmund have agreed to sign Slovenia international Kevin Kampl in January.
Cardiff have agreed to sell Norwegian midfielder Mats Daehli to Freiburg in January.
Galatasaray have announced they have reached an agreement to sign Didier Drogba.
The former Chelsea striker will join the Turkish giants from Chinese side Shanghai Shenhua on an 18-month deal.
His representatives revealed on Twitter that the Ivory Coast international would join up with his new side following the African Nations Cup.
Gala confirmed the deal on their official website.
Drogba's capture is the second marque signing within a week for Gala, coming hot on the heels of the arrival last week of Holland midfielder Wesley Sneijder from Inter Milan.
Drogba said through his representatives, Sports PR Company, on Twitter: "The opportunity to play for this great club was an offer that I could not turn down.
"I am looking forward to playing in the Champions League again, against the best clubs in Europe."
An emotional reunion with Chelsea is not possible, though, after the holders crashed out of the competition in the group stage.
Drogba's move to Turkey brings to an end a six-month stint in China.
The 34-year-old joined Shanghai last June soon after helping Chelsea win their first Champions League title, the striker scoring the winning penalty in Chelsea's final shootout triumph over Bayern Munich.
Drogba penned a two-and-a-half year deal reportedly worth £200,000 a week with Shanghai but was repeatedly linked with a move back to Europe in recent months.
Last month Drogba returned to train with Chelsea during the Chinese off-season in preparation for the African Nations Cup in South Africa.
FIFA rejected a special request from the striker for him to join a club on loan outside the transfer window, amid speculation linking him with Juventus, AC Milan and Liverpool, among others.
Despite his protests to the contrary, reports persisted that Drogba's move to China had not worked out, largely due to boardroom wrangling, and he has now left the Far East to return to Europe.
Gala are five points clear at the top of the Super Lig standings and are through to the last 16 of the Champions League, where they face Schalke.