Tampa Bay Buccaneers head coach Bruce Arians is unsure if star duo Antonio Brown and Rob Gronkowski will return for Sunday's NFL showdown with the Washington Football Team.

Brown has missed Tampa Bay's last two games due to an ankle injury, while Gronkowski is battling to overcome back spasms that flared up in the loss to the New Orleans Saints on October 31.

Super Bowl champions the Buccaneers are coming off the bye and practiced on Monday, though neither Brown nor Gronkowski were involved.

"I think you still have to worry a little bit about Gronk and I don't know if AB is going to be back," Arians told reporters.

"And Carlton [Davis III] will stay on IR [injured reserve]. We'll see if those other two guys are game-ready.

"It's one thing to practice, it's another thing to throw them out there in a game."

Gronkowski had four touchdown receptions in the season's first two games and 16 grabs overall prior to suffering his initial rib injury in Week 3 before missing four games.

Brown's average of 83.6 receiving yards per game is highest among all Buccaneers pass-catchers.

The Buccaneers (6-2) lead the NFL in points scored per game (32.5) and passing yards per game (327.5).