ENGLEWOOD, Colo. — Rookie quarterback Drew Lock is going to miss "a little bit of time" with a right thumb sprain, Head Coach Vic Fangio announced Wednesday.

Fangio said the Broncos would not sign another quarterback "right now."

Asked if Lock's injury would impact the construction of the team's 53-man roster, Fangio said the Broncos will "cross that bridge when we need to next week."

The Broncos must trim their roster to 53 players on Aug. 31.

Noah Fant (ankle) also did not practice Wednesday, but Fangio said he thinks Fant is "fine."

"I don't think it's anything serious," Fangio said.

Ron Leary (knee) was not at practice on Wednesday. The veteran guard sat out Monday's game against the 49ers.

"It's a concern, but I think Ron's doing a good job for the most part of managing it. I think our trainers and Mike [Munchak] are doing a good job of managing it," Fangio said. "We're trying to get him ready for the regular season and see where it goes."

Cornerback Bryce Callahan (foot) also will not practice this week or play in Saturday's game against the Rams.

"It's kind of gotten sore on him a little bit," Fangio said. "He can play. He could've played the other night, we're going to just be prudent with it and not practice him this week — nor play him — just to make sure he's ready."

Linebacker Todd Davis (calf) remains out after suffering an injury on July 18.

"He won't practice today," Fangio said. "He probably won't practice this week at all. He's a little bit behind where we had hoped, so it's still up in the air."

Fangio said it's "too early" to speculate on if Davis might miss the Broncos' Week 1 game against the Raiders but that "it's definitely a possibility."

Tight end Jeff Heuerman (shoulder), linebacker Joe Dineen (hand), linebacker Joe Jones (upper arm), fullback Andy Janovich (pectoral) and running back Theo Riddick (shoulder) also did not practice.

Fangio said safety Su'a Cravens (illness) would practice and that he believed safety Will Parks (hamstring) would practice "to some degree." Both players were in helmets and jerseys.

Outside linebacker Malik Reed, running back Khalfani Muhammad and safety Kareem Jackson also were in helmets and jerseys.