Javier Hernandez's time at Manchester United is over after the striker signed a three-year deal with Bayer Leverkusen.
The Mexico international is the second forward player to leave Old Trafford for the Bundesliga on Monday after Adnan Januzaj joined Borussia Dortmund on loan.
Hernandez was loaned out to Real Madrid for the 2014-15 season following Van Gaal's arrival at Old Trafford, scoring nine goals in 33 appearances.
Leverkusen will add the 27-year-old to their squad for the upcoming UEFA Champions League campaign, and hope he can add a new dimension to Roger Schmidt's side.
"I know with the English Premier League and the Primera Division in Spain two of the three major European leagues," Hernandez told Bayer's official website. "Now I want to experience the Bundesliga.
"I have heard a lot of the great stadiums in Germany, where the fans are unique.
"The Bundesliga is set up extremely offensively, it is a great attraction for me.
"It's wonderful that I now get to play for a club like Leverkusen. Bayer is a great opportunity for me, I want to achieve something here."
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