According to Spanish news outlet Fichajes.net, West Ham are looking at Alcacer 'closely', being keen to strengthen their striker options this summer.
After failing to add to their options in attack in the January transfer window, the Irons want to sign a striker especially if they qualify for European football, especially if they manage to qualify for the UEFA Champions League.
Alcacer has struggled for goals with Villarreal in La Liga this season, getting just five goals and three assists in 20 league games.
On the other hand, he has thrived in the UEFA Europa League, getting five goals and an assist in just six games, and his performances in Europe have been enough to attract the interest from David Moyes' side.
Apart from Alcacer, West Ham are also interested in Sevilla's Youssef En-Nesyri, who was a target for West Ham in January, when they were searching for a replacement for Sebastien Haller, who moved to Ajax in January.
En-Nesyri has been in incredible form this season for Sevilla, scoring 21 goals in 43 games in all competitions.
However, the Sevilla striker could go for a very large fee, and so Alcacer might seem like a more realistic option, yet Villarreal manager Unai Emery 'would not be too happy' to have the 27-year-old striker 'snatched' away from him.
Alcacer's contract with the Spanish side runs until 2025, and the report claims that in order to tempt Villarreal to cash in on him, West Ham need to offer €25 million, as Villarreal are only 'willing to negotiate' a deal with him for that transfer fee.