ENGLEWOOD, Colo. - Denver Broncos quarterback Drew Lock has a "pretty severe strain and bruising" in his ribs but no fracture, further testing revealed, a source told ESPN.

Lock is expected to miss practice time this week with the injury, and his status for Sunday's game against the Miami Dolphins is in doubt.

He was hurt in Sunday's loss to the Las Vegas Raiders.

Lock already has missed two games this season and most of a third with a right (throwing) shoulder injury. He returned in Week 6 against the New England Patriots and has started the five games since.

Lock is in his first full season as the team's starter. Coach Vic Fangio said even if Lock has somehow recovered enough physically by week's end to play against the Dolphins, any missed practice time this week would factor into any decision of him starting, as well.

"That will definitely enter into the equation,'' Fangio said Monday. "We definitely want Drew to have a good week of preparation, so he's ready to play the game. That could enter into the equation as we go through the week.''

Brett Rypien has been Lock's backup over the past five games and started one of the games Lock missed earlier this season -- the Broncos' Week 4 win over the New York Jets. The Broncos also have Jeff Driskel on their 53-man roster -- he started their Week 3 loss to the Tampa Bay Buccaneers -- and Blake Bortles is on the practice squad.

Lock was hit from behind by Raiders defensive end Alden Key in the second quarter of Sunday's loss and was visibly hurting after the play as he also received some treatment from the Broncos' medical staff following the series.

Lock was again slammed to the ground late in the first half on a hit by Raiders defensive tackle Clelin Ferrell -- Ferrell was penalized for roughing the passer. Three plays later, Lock threw his second interception of the first half, this one at the Raiders' goal line.

Fangio said after Sunday's game he told the team's offensive coaches to keep a "close eye'' on Lock in the second half, but he finished out the game.

Lock has struggled mightily at times since returning from his shoulder injury. He has thrown 10 interceptions over the past five games, six over the past nine quarters, including four Sunday. He is currently last in among the league's starters in completion percentage (55) and only Sam Darnold has a lower passer rating than Lock's (66.5).