ENGLEWOOD, Colo. -- It's almost time for the Denver Broncos to decide if they should throw a few more crumbs rookie quarterback Drew Lock's way.

Lock, a second-round pick for the Broncos in this past April's draft, is one of three Broncos on injured reserve who is eligible to return to the practice field as early as Monday (running back Theo Riddick and tight end Jake Butt are the others). Lock was placed on injured reserve Sept. 2 after he suffered a right thumb injury in the preseason.

Earlier this season, when asked what Lock would do during his time on injured reserve, Broncos coach Vic Fangio said: "It's a crumb here and there. Crumbs can add up and make a loaf of bread."

Before Sunday's win over the Los Angeles Chargers, Lock did some throwing work on the field -- it was the first time he had thrown in pregame since his injury in August. Earlier this week, he said it "felt great" to throw and he has not had a splint on his right (throwing) hand and wrist for the past two weeks.

By league rules, the Broncos can bring as many as two players back off injured reserve during the season if those players were on the active roster when they went to injured reserve. It's why Lock, Riddick and Butt were kept on the roster when cuts were made to 53 players Sept. 1 and were then moved to injured reserve the next day.

Those players can return to practice six weeks from the day they went to injured reserve -- that would be Monday -- and could be in uniform for a game eight weeks from the time they went to injured reserve -- that would be the Broncos' Week 8 game Oct. 27 in Indianapolis.

At the moment, Lock and Riddick are the most likely of the three players to be moved to the roster. The Broncos have made it no secret they believe Lock's participation on the practice field would be beneficial. On injured reserve, he has attended practices and done conditioning work on a side field, but he cannot participate in any drills or throw to any receivers. Lock has also been immersed in the Broncos' STRIVR system -- a virtual-reality training program used by a long list of businesses -- as well as all of the quarterback meetings and team meetings.

There have been no rumblings or public hints the Broncos would want to use Lock in a game in the near future -- Joe Flacco has completed 66.7% of his passes and certainly done his part in the Broncos' offense.

"You have to be creative when a guy is out like he is, whether it's in the meetings, on his own -- there is technology that we use," said offensive coordinator Rich Scangarello. " ... When you really watch out here in practice, the backup hasn't gotten a rep in practice in three weeks. You just don't in the NFL. If Drew was here [at practice], he'd have to learn visually and through Joe and through the film and then on his own finding ways to do that by mentally taking reps and being creative with how he can be better at what he needs to get better at."

Broncos president of football operations/general manager John Elway has largely preached patience when it comes to Lock. But when he was placed on injured reserve, Elway said it was important for Lock to understand "it's not a year off for him" and to "understand what he's doing."

Asked Thursday about Lock's work so far, in terms of his grasp of the offense, Scangarello said: "I think he's done a great job. He had a very long way to go when he first got here, just from his foundation, and I've said this before, I just see in this league, especially if you're a spread quarterback, the ability to not play early on is everything. And you gain confidence and learn from others and I think he's done everything he can to do that."