Question: can a player play in uefa competition for more than one club in the same season

Answer: No, In association football, a player who has appeared for a football club during a knockout cup but subsequently transfers to another club is ineligible to play for the new club in the remainder of that season's cup competition. Such a player is said to be cup-tied i.e. tied to their original club for the duration of the cup tournament. They become eligible for their new club in the following season.