Lock sprains thumb, to miss start of season

Broncos quarterback Drew Lock is expected to miss the start of the regular season due to a sprained right thumb sustained in Monday’s loss to the San Francisco 49ers.

After the game, Lock said X-rays were negative and he would have an MRI on Tuesday. He will not need surgery. The NFL Network first reported the injury, which a source confirmed.

Lock, competing for the backup job with Kevin Hogan, was injured in the third quarter when he was flushed out of the pocket. As he was attempting to throw the football away, he was tripped up and jammed his thumb into the turf. He stayed in the game for one more play.

Dr. Steven Shin, director of hand surgery at Cedars-Sinai Kerlan-Job Institute in Los Angeles and a hand consultant for the NFL’s Rams, said in a phone interview that Lock likely did not sustain a complete tear of a ligament because no surgery will be required.

“A Grade 2 is a partial tear of the ligament and (the recovery time) is usually 5-6 weeks and then start throwing,” Shin said.

Shin said 90 percent of thumb ligament injuries involve the ulnar collateral ligament of the metacarpophalangeal joint. A Grade 1 sprain is mild and requires 2-3 weeks recovery and a Grade 3 injury is a complete tear and requires surgery and 10-12 weeks of recovery.

The usual timetable for a Grade 2 sprain would keep Lock from throwing until at least Week 4 of the regular season and a new rehabilitation clock would start once he begins to practice.

Among the athletes who have sustained torn ulnar collateral ligaments and were operated on by Shin include Los Angeles Angels outfielder Mike Trout, Houston Rockets center Clint Capela and Oklahoma City Thunder point guard Chris Paul.

Shin said it will be important for Lock to keep moving the other two joints in the thumb and his wrist and other fingers as his injury heals.

“The first two weeks, it’s going to hurt to move around so they will want to immobilize that joint with a brace,” Shin said. “But I encourage movement of the other two joints, the one by your nail and the one closest to the wrist.”

In three preseason games, Lock is 31-of-51 passing for 254 yards, one touchdown, one interception, and a 71.9 rating. He has been sacked six times.

“I thought Drew showed some flashes of improvement (on Monday night), made some nice throws, moved around well, but I’m sure it wasn’t perfect,” coach Vic Fangio said. “Again, he’s improving and that’s what we’re looking for right now.”

If the Broncos felt Lock was on track to be Joe Flacco’s backup, it might have made Hogan expendable and created an extra roster spot. But Lock’s injury could create a path for Hogan to be on the Week 1 roster and until Lock returns to full health.

Hogan is 13-of-30 passing for 104 yards, one interception and a 38.8 rating in the preseason.