Samir Nasri explained his decision to leave Olympique Marseille for Arsenal in 2008.
The former France midfielder joined the Gunners for a fee of 16m.
Nasri told Befootball: I was indebted to Marseille.
"I could have moved to Arsenal for free, as many other players have done, but that was not an option for me.
"This is my city, my club, I trained there, I could not go for zero euros and say: 'Ciao, I used you.'
"It was impossible, I had to extend the contract and pay compensation to the club."