The in-demand teenager has been unable to come to an understanding with his employers about a new contract, and Barca could exploit the situation to secure his services
The Spain Under-19 international has emerged as one of the most promising talents of his country and made headlines last month when he scored a goal in Valencia's 3-0 friendly win over Roma.
Alcacer has a contract with Valencia until the summer of 2013, and both parties have been locked in talks regarding an extension, so far to no avail.
Spanish sources suggest the 18-year-old has a clause in his current contract which will allow him to leave for free if he is not part of Valencia's first team next year.
AS such, Barcelona are believed to be closely monitoring Paco Alcacer's situation after reportedly having a €3 million offer for the striker rejected by Valencia in the summer.