The Spaniard was one of Mark Hughes's most high-profile signings from Real Madrid last summer.
The 25-year-old - who has started just four games since the beginning of February - admits that playing in the Championship was not on his radar when he signed, but he is more than happy to stay.
"I signed my contract here for four years," said Granero.
"I was not thinking about going to the Championship when I joined but that is the reality now. I like life in London. We now prepare for life next season. The club will have to decide, not me.
"Many things have happened during the season and we have not been able to get over them. It is hard to analyse. It is not just one thing that has gone wrong. It is many things together.
"We hope we learn from that and next season we do it another way. It was difficult for us but let's finish the season properly for the fans. They have been outstanding for us this season and we have felt them behind us from the beginning."
Joey Barton - who launched yet another Twitter tirade at the club on Sunday - also says it is QPR who will decide if he returns, but he reiterated his desire to remain with Marseille.
He told Telefoot: "I want to stay but unfortunately it doesn't only depend on me. I belong to another club.
"Last week I had a talk with l'OM officials and I may prolong my stay here."