Argentina international Mascherano has been used sparingly this season, making just six La Liga appearances, and there are several reports suggesting he will look to leave the Camp Nou in the next transfer window.
The 33-year-old has hinted he could search for first-team football elsewhere whilst his team-mate Lionel Messi has also increased speculation regarding the midfielder's future with his recent comments.
When quizzed about Mascherano's future, Valverde admits the situation is still up in the air although he insisted the former Liverpool ace is fully committed when asked to play.
"The winter transfer market [January] hasn't arrived yet, we wait for that to begin," he said. "And that's one of the questions we have to look at but for the time being he's still ours and whenever he has played, he has played well.
"He's committed to the club, on and off field, and as long as he's here we don't need to think about anything else."