The transfer window isn't closed yet in Turkey as it is in Italy. Trabzonspor have tried, in the last days, to get Milan's Sosa. The player has said "no" though, he'll stay a rossonero and will tell both clubs soon. The Argentinean player has decided to stay at Milan despite the fact his contract ends in 2018 and the important offer Trabzonspor made: €5m per season for the next 3 years, and a 5m signing bonus.
The player left Besiktas last summer to play at Milan, and after a year, he seems like having made the same decision refusing Turkey to stay in Italy.