Before being sold to Galatasaray last summer, Gomis spent the season on-loan in France with OM.
He said: "OM? I had the chance to play a year in the club of my heart. I knew I had to go back to Swansea, and I never planned beyond my loan. As they say, nobody is irreplaceable, we are all in transit.
"The main thing was to leave the house clean in the club of my heart. I'm behind them, I'm happy with my career and I wish them a great end to an exciting season."