Dembele, 20, made a move to Barcelona from Borussia Dortmund in August a year ago for a reported €105million.
A serious hamstring injury within his first few matches has restricted the Frenchman's chances of impressing this season.
Barcelona's French winger, Ousmane Dembele, revealed on Monday that he will stay in Barcelona to prove himself and will not leave the club by the end of the season. As many as four clubs submitted significant financial offers for the World Cup victor, who is expected to sign a three-year contract.
Valencia, meanwhile, have made just one change to the team that beat Espanyol 1-0 last week, with Ruben Vezo coming in to replace former Barcelona defender Martin Montoya at right-back.
"I've worked very hard on my fitness the past few months, I have spent a lot of time in the gym because I am getting exhausted very quickly".
Dembele responded, "At Barcelona, I have a better lifestyle". That loss ruled Dembele and his teammates out of the competition.
Lionel Messi could be among a number of key players rested from Barcelona's game against Celta Vigo on Tuesday, according to coach Ernesto Valverde. A win would take the league leaders 14 points clear of second-place Atletico Madrid, who play on Real Sociedad away on Thursday.