"I would say Calvin Johnson because of size," Grimes said when asked to name the NFL's toughest receiver to defend, per ESPN.com's James Walker. "He's huge. He's like an NBA small forward playing NFL receiver, and he still has the ability to run routes. But there's a few of them that's really good. I like Julio a lot. But Calvin Johnson is just huge, and that combined with his athletic ability presents a lot of problems."