On Sunday, Peyton Manning again looked like a quarterback who perhaps has hung on for one season too long, with his passes too often wobbling into the hands of players on the wrong team.

But he did manage to summon just a few moments reminiscent of his past greatness, some of which were rewarded by his receivers and some of which weren’t.

The final result was that Manning and the other members of the Denver Broncos’ offense did just enough to help their superb defense keep the team unbeaten. The Broncos won in Cleveland, 26-23, on an overtime field goal by kicker Brandon McManus. They take a record of 6-0 into their bye week.

The question is: Can it continue to work this way for the Broncos?

The Denver defense clearly appears capable of doing its part and handling the heavy lifting.

But can Manning do his part, even as diminished as it has become?

The end seems near for Manning, whose deterioration as a passer once more was evident Sunday. The day began with a quarterback matchup of Manning vs. Browns career journeyman Josh McCown, and it was not clear which one you’d rather have at this point. One team in the game had a quarterback who had been highly productive lately. The other one had Manning.

Manning contemplated retirement last offseason before opting to return for another season in Denver. He accepted a pay cut to stay. With the way Manning has played this season, it’s not clear if he made the right choice.

Sunday was a case in point. Manning continues to look uncomfortable when performing the rollouts featured in the offense of Gary Kubiak, the Broncos’ first-year coach. Most of Manning’s best moments this season have come when the Broncos have put Manning in the shotgun formation and run Manning’s offense, not Kubiak’s. The blending of the two has been far from seamless.

Manning threw three interceptions Sunday and had a passer rating of 53.3. He threw one interception that was returned for a touchdown by Cleveland’s Karlos Dansby in the fourth quarter. He threw another interception in overtime, snagged by the Browns’ Barkevious Mingo, that could have cost the Broncos the game.

But it didn’t. And Manning also had some good moments. He threw for 290 yards and a touchdown. He had two 100-yard receivers in the game, Demaryius Thomas and Emmanuel Sanders. He had a 75-yard touchdown pass to Sanders in the fourth quarter.

His numbers would have been better if Thomas hadn’t had two costly drops, and if a long would-be completion to Sanders at the end of regulation hadn’t been ruled incomplete after a replay review.

But make no mistake: The defense won the game for the Broncos, just as it has been doing all season. Cornerback Aqib Talib had a touchdown on an interception for Denver, the Broncos’ fourth touchdown this season while on defense. The Broncos allowed two touchdown passes to McCown but intercepted him twice and limited him to a passer rating of 63.3 on 20-for-39 throwing accuracy. McCown had 213 passing yards.

The injuries are beginning to pile up a bit for the Denver defense. One pass rusher, DeMarcus Ware, was on the inactive list for the game because of a back injury. Another, rookie Shane Ray, exited the game with a knee injury.

The Broncos are strikingly fast on defense. Sometimes it seems that their best chance to score is when their defense is on the field.

Manning, for the season, has seven touchdown passes and 10 interceptions. Two seasons ago, he had 55 touchdowns and 10 interceptions. Even last season, it was 39 touchdowns and 15 interceptions. He is not the quarterback that he was even a year ago.

But can he be the quarterback who does just enough to get a terrific Denver defense to a Super Bowl? That will be one of the league’s most intriguing story lines for the remainder of the season.