The former Atalanta star is waiting on a doping suspension to come to an end.
He has also been training in Spain in preparation for a return to pro football.
Gomez told Renate's website: "Taking advantage of this opportunity that the club has given me, I am happy to share training with the team.
"I am very happy. At 36, my goal is to return to playing, which is the thing that makes me happiest. The light at the end of the tunnel can be seen and we can start training again."
Gomez's ban ends in October 2025.