Redskins' Horton 'tweaks' knee

Posted by ESPN.com's Matt Mosley

Redskins safety Chris Horton injured his knee Thursday and had to leave practice, but coach Jim Zorn said he probably wouldn't have an MRI test. The other injury news is that punter Hunter Smith aggravated his groin injury and will be inactive for Sunday's game against the Falcons. The Skins are expected to sign Sam Paulescu to fill in for Smith, so they'll have to make another roster move.

"I don't want to put down Hunter because he's healing," Zorn told reporters Thursday. "I don't want to put him down right now."

Of Horton's injury, Zorn said: "I don't know the extent of it, but he couldn't finish practice. I hope he'll be fine. I hope he'll practice tomorrow."

The Redskins will face a Falcons team that has lost two straight games for the first time in the Mike Smith era.