The Spain international has signed a five-year extension with his hometown club to end speculation of a move away - with Liverpool and Real Madrid among the clubs reportedly keen on his signature.
Alcacer has made 22 appearances in all competitions this season, netting eight goals as Valencia have charged up to fourth in La Liga, as well as scoring three goals in five Spain outings since his debut in September.
Now the 21-year-old hopes to guide Valencia back into the Champions League where they can battle with Europe's elite.
"I am delighted and proud to be continuing at Valencia for five more seasons," he told the club's official website.
"I want to thank the club for the confidence in me that they are showing.
"What I have to do now is pay them back by scoring goals and giving everything that I have to help the team.
"I am going to continue working, in order to become a better player and to take Valencia back to where the club belong.
"The Champions League is the main objective and I personally want to play an important role for the team."
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