Did Tim Tebow do enough in Sunday’s second half loss to San Diego to unseat Kyle Orton as Denver’s starting QB? (Joe Mahoney/AP)

When would the team’s struggles with Kyle Orton at quarterback force new coach John Fox to make a change? When would the chorus of “We want Tebow” from the Mile High faithful become too loud to ignore? When would one of the most popular players in the NFL who has yet to accomplish anything finally get his chance to be “the guy” for the Broncos?

On Sunday the wait ended as Tebow replaced Orton with Denver trailing San Diego 23-10 to start the second half.

Despite a shaky start that saw him complete just one of five passes for zero yards, Tebow found some rhythm in the fourth quarter, showing his running ability with a 12-yard scamper and then tossing a 28-yard screen pass to Knowshon Moreno that went for a touchdown to pull the Broncos within 26-24.

Tebow was unable to lead his team all the way back, but the moxie he displayed on Denver’s final drive showed why the fans have been clamoring to see more of the second-year signal-caller — and why the Broncos may turn the reins over to him full-time following their bye week.

Denver got the ball back with 24 seconds left in the game, trailing 29-24. On the first play Tebow threw a deep out pass down the right side to Brandon Lloyd who made a phenomenal catch that was initially called incomplete — likely because the sideline official could not conceive of such a ridiculous catch — but was overturned for a 20-yard completion. Tebow’s next throw went down the middle for 31 yards to Daniel Fells. With two seconds left he spiked the ball at the Chargers 29-yard-line, giving Denver one shot at the winning touchdown. The hail mary fell incomplete in the end zone, but on the final play Tebow danced around the pocket, evading pass rushers with the type fleet-footedness Orton could only dream of possessing.

Tebow isn’t going to become Cam Newton overnight — if ever. He still looks uncomfortable in Denver’s offense at times and he doesn’t have the experience or connection with the receivers that Orton does. His struggles in practice have been well-documented and knocked him out of the starting QB conversation early in training camp. And then there’s the issue of his throwing motion.

All that said, the Broncos are 1-4 and Orton — who completed just 6 of 13 passes for 34 yards and an interception in the first half — is not doing himself any favors.

With their bye this week, it may be the perfect time for the Broncos to start giving Tebow first-team reps (at quarterback) in practice and see what he can do in Week 7 at Miami. At this point, what does Denver really have to lose?