Veteran defender Martin Skrtel, signed by Atalanta to boost their defence as they make their Champions League debut this season, has left the club after only 24 days, the Serie A side said on Monday.
The 34-year-old Slovakia international, whose career has included nine seasons at Liverpool, did not play a match for the club which he joined as a free agent on Aug. 9.
"Atalanta announces that it has ended the contract with Martin Skrtel by mutual consent," the club said in a statement.
Later on Monday, Skrtel, previously at Fenerbahce, joined fellow Turkish club Istanbul Basaksehir.
Atalanta also said that they had signed Denmark defender Simon Kjaer on loan from Sevilla.
Coach Gian Piero Gasperini said after Atalanta's 3-2 home defeat by Torino on Sunday that Skrtel had been struggling to adapt to the team's tactics.
"He said that at his age, he had trouble playing in a three-man defence which is understandable," Gasperini said. "He arrived after we had started training, and he had difficulties."
"It was difficult for him to adapt to our style of play, which is understandable."