Tennis fans often occupy two camps rooting for either Roger Federer or Rafael Nadal.

The iconic champions could collide for the first time at the US Open in the semifinals.

Watch: Vandeweghe Topples Pliskova

First-time US Open semifinalist CoCo Vandeweghe favors Federer because of his attacking style.

"This is going to give me crap but I'm a Federer person," Vandeweghe said when asked which champion she supports. "I think it was more I liked how he played. He was more of an aggressive player, while Nadal, in the early stages of his career, was more of a grinder, grinded opponents down."

The New York City-born, California-raised Vandeweghe says the rivalry reminds of her the Pete Sampras-Andre Agassi clashes. She supported Sampras in that rivalry and tried to emulate his serve.

"Similar to like Agassi and Sampras, I liked Sampras more than I liked Agassi, even though Agassi threw in haymakers and was an unbelievable player," Vandeweghe said. "But my game was modeled off of Sampras, at least my serve. So I think I have spent more time watching Sampras than I did Agassi. So I will probably get some crap for that one."

Photo credit: Mark Peterson/Corleve