From Major League Bastian :

For those who asked via Twitter, yes, Perez did do John Cena’s “You can’t see me” move after striking out Jarrod Dyson for the second inning in the ninth. Alas, Perez declined to discuss the gesture, or his reasoning behind it. Maybe Perez was just amped up. They don’t call him Pure Rage for nothing.

Also, “Pure Rage” might look better on a t-shirt than say, “Contrived & Lame”