Well, I havent been following this, but they are trying their hardest to keep him, maybe if they make the ECL he will decide to stay for another year.
The only way they will keep Marquez is if they restructure his contract and pay him more or if they continue to keep his selling clause high. Deschamps likes him and I think that he wants him to stick around. I don't know if playing in the ECL with Monaco would motivate him. He's already done it before and the other teams that have reportedly been after him will likely be playing the Champions league (Real Madrid, Deportivo, Barcelona, Manchester United)