Besiktas remain hopeful that a deal for the 31-year-old could still be completed but the Turkish club now face competition from two of Europe's heavyweights
The 31-year-old has a year remaining on his current deal with Fiorentina and spent last season on loan at Besiktas where he scored 28 goals in 41 appearances.
The striker has confirmed that he will not be making the move permanent due to the political situation in Turkey but Besiktas remain hopeful that a deal can be agreed for the Germany international, despite interest from both Barca and Dortmund.
“Our fans are feel hopeful about Mario Gomez returning,” Besiktas spokesman Metin Albayrak told Dogan News Agency.
“We're monitoring his situation closely but we know that he is in serious talks with Barcelona and Borussia Dortmund. Obviously he is difficult for us.“I spoke with Slaven Bilic on the phone this morning. He said that they're not interested with Mario Gomez.”