Portugal winger Simao is leaving Atletico Madrid and will join Turkish side Besiktas.
The 31-year-old, who scored a penalty in Atletico's 1-0 Copa del Rey last 16 first leg win over Espanyol, will hold a news conference on Thursday at the Calderon stadium.
"It's been an honour to have had him in my team," Atletico coach Quique Sanchez Flores said.
"He has been a spectacular professional with influence both on and off the pitch," he said, adding that the club were mulling buying a player to replace him.
Simao's exit was expected and he was cheered from the pitch by the Atletico fans when he was substituted in the second half.
He joined from Benfica in 2007, becoming one of the club captains, and previously had stints with Barcelona and Sporting Lisbon.
Valencia Midfielder Manuel Fernandes Set To Finalise Besiktas Loan Move it's a done deal
Valencia midfielder Manuel Fernandes arrives in Turkey ahead of sealing a six-month loan switch to Besiktas.
Valencia midfielder Manuel Fernandes has arrived in Turkey ahead of sealing a loan move to Besiktas until the end of the season.
The ambitious club have been linked with Atletico Madrid winger Simao and Werder Bremen attacker Hugo Almeida in the past 24 hours, while Fernandes has been a long-term target for the Black Eagles.
The 24-year-old has seen his first team opportunities limited at the Mestalla this season due to the arrival of the likes of Mehmet Topal and Tino Costa, and will arrange a short-term deal until the end of the season.
Various reports from Spain suggest that both parties have already reached an agreement, and the deal includes an option for Besiktas to make the deal permanent at the conclusion of the contract.
The big-spending Turkish club are coached by former Real Madrid coach Bernd Schuster, and contain ex-Los Blancos playmaker Guti in their ranks.
OUR ATTACKING POWER
AND IT'S JUST HAPPENED BUT WE ALSO MADE A DEAL WITH HUGO ALMEIDA
IT'S A FLASH NEWS
IT'S ALL OVER IN THE MEDIA in Turkis it basically says that his deal is for 3.5 years