Drew Lock has accepted his rookie year isn’t going according to plan. The quarterback, Denver’s second-round draft choice in April from Missouri, has been on injured reserve since suffering a right thumb sprain in the Broncos’ third preseason game.

Lock is ahead of schedule in his rehabilitation and has been throwing a football for a couple weeks. But with the injury setback and an understudy label behind first-year veteran starter Joe Flacco, Lock’s rookie season features the tall task of getting better … without playing.

“I realize that I can either get wrapped up in the negative things or get wrapped up in my work,” Lock said in an interview with The Denver Post after practice last week. “I’m getting wrapped up in my work and trying to get better every day. That means still learning even when I’m not participating, and focusing on the (positive) here for me. I have to figure out how to be the best quarterback I can possibly be without actually taking reps.”

Lock is eligible to begin practicing Monday, six weeks after he was placed on injured reserve. But because of the Broncos’ short turnaround to Thursday’s game against Kansas City, Lock’s first true practice won’t be until next week.

The Broncos have three weeks to reinstate Lock to the active roster or keep him on injured reserve for the rest of the season. That means the quarterback is eligible to return to game action for Week 9’s home showdown against Cleveland on Nov. 3. Related Articles Kiszla: At this point in storied NFL career, is old Tom Brady any better than Broncos journeyman Jeff Driskel?

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Per NFL roster rules, teams can pull two players off injured reserve and put them on the active roster during the season. It’s unclear if Lock will be one of those two selections. Tight end Jake Butt (knee, placed on injured reserve Sept. 2), running back Theo Riddick (shoulder, Sept. 2) and wideout Tim Patrick (hand, Sept. 11) are other potential candidates to return to the roster.

For Lock’s part, he remains focused on immersing himself in the offense, learning under Flacco and making sure his thumb is 100 percent healthy should he get activated. Brandon Allen, acquired off waivers on Sept. 1, is currently Flacco’s back-up.

“It’s just about getting the strength and flexibility back,” Lock said. “Those are my two main goals throughout every day, and there’s no pain when I do those (thumb) exercises, so that makes me feel good about it.”