The Ghana international, who played at the World Cup in Brazil, spent the second half of last season on loan at French side Valenciennes, where he scored nine goals in 16 games.
Transfer - ALGERIA - Carl Medjani and Kevin Constant join Trabzonspor
Algeria international Medjani, 29, has signed a three-year deal after Monaco agreed to terminate his contract. Constant, who can play in defence or midfield, has joined from Italians AC Milan for an undisclosed fee.
LEGENDS - IVORY COAST - Drogba will leave Galatasaray
The 36-year-old won the Super Lig with Gala in his first half-season. The Ivory Coast international added: "You can't make happy people all the time but I made them happy for 340 days out of 365 a year."