"I can't put any pressure on it. It's kind of funky. I've never had this particular injury before," Hall said. "It could take a couple of days, it could take a couple of weeks, so they're cool with me just sitting down for now and give it time to rest and heal up."
Hall wore an immobilizing boot as he watched practice. He was hurt Monday when he lost his footing trying to defend rookie free agent receiver Skye Dawson, who has been one of the surprise standouts of camp.
"The young guy, he ran a great route," Hall said. "Coming out of my break, something just gave out."
Hall said he initially thought he tore a ligament. He said there is no fracture, and that his Achilles is fine.
"A lot of guys were joking, `Yeah, you wanted a day off.' I'm like, `Yeah, I wanted a day off, but not like this," he said.
Hall becomes the fourth Redskins defensive player to suffer a significant setback since the opening of camp. Defensive end Adam Carriker had a third surgery on his right knee and is expected to be sidelined another four to five months. Linebacker Keenan Robinson is out at least three months with a torn left pectoral muscle, and defensive end Jarvis Jenkins was hit with a four-game suspension after testing positive for a performance-enhancing drug.
Also Tuesday, left tackle Trent Williams sprained his left wrist when he fell while blocking a play during the afternoon practice. The wrist was heavily taped as he walked off the field.
"It's really nothing, though," he said. "Just stunned a little bit. I'll be fine."
Several other players missed all or part of practice for various injury-related reasons. Receiver Donte Stallworth, guard Adam Gettis and linebacker Jeremy Kimbrough are nursing hamstring injuries. Safety Brandon Meriweather is still recovering from a torn ACL in his right knee, and running back Chris Thompson continues to feel the effects of a torn ACL in his left knee. Safety Jordan Pugh left early because he "wasn't feeling very good," according to Shanahan.
Also, running back Tristan Davis, who has been on the practice squads for six NFL teams but has never appeared in a regular season game, has left the team.
"Tristan Davis came to my office earlier this morning and said that his heart wasn't in playing football anymore," Shanahan said. "So he retired."