Oakland Raiders head coach Jon Gruden thinks that Pittsburgh Steelers wide receiver Antonio Brown may have the best work ethic in football.

The two teams will meet on Sunday in Oakland, and Brown figures to be a popular fantasy play against a Raiders squad that has struggled all season long.

While Brown may be having a somewhat disappointing season by his standards, he's still one of the most dangerous playmakers in the league.

And Gruden seems to know exactly why the six-time Pro-Bowl selection continues to thrive on the field.

Here's what Gruden had to say on Wednesday about Brown's practice habits, courtesy of ESPN's Paul Gutierrez:

“They move him around everywhere. You don’t know where he’s going to be. He can run every route you dream up. I say that about other receivers, but he can run double moves, he can run by you, he can run crossing routes, he’s very good after the catch. What’s the greatest thing about this man, I’ve told all of our receivers, if you get a chance to watch him practice, you’ll see what unlocks the greatness in him. He’s the hardest working man, I think, in football. Hardest working player I’ve ever seen practice. I’ve seen Jerry Rice, I’ve seen a lot of good ones, but I put Antonio Brown at the top. If there are any young wideouts out there, I’d go watch him practice. You figure out yourself why he’s such a good player.”

Considering that Rice has long been considered one of the hardest-working players in NFL history, that is undoubtedly very high praise from Gruden.

The Steelers will look to get back on track this week after suffering a tough 33-30 home loss to the Los Angeles Chargers.