DENVER — When the Denver Broncos finished out a wobbly 31-13 victory over the Indianapolis Colts at Empower Field at Mile High, rookie quarterback Bo Nix acknowledged the Broncos clinching the team’s first winning season since 2016 and being in prime position to make the playoffs for the first time since winning Super Bowl 50 to close out the 2015 season.

“It speaks to our team,” Nix said. ” … Good teams respond to days like [Sunday], playoff teams find a way to win.”

But Nix was just as quick to say that he must learn from and improve from of the erratic performance he had against the Colts, especially with three more regular-season games and probably the playoffs approaching, as the Broncos have a 94% chance to qualify for the postseason according to ESPN’s Football Power Index.

Despite hitting the three-touchdown-pass mark for the third time in his young NFL career on Sunday, Nix threw three interceptions in a game for the first time as a professional. They were part of a day in which the rookie went 20-of-33 for 130 yards, his second-lowest output of the season, and the Broncos could only muster 193 yards of total offense.

The casual observer might look at the 18-point margin of victory and the 21-point fourth-quarter barrage and assume everything went well. But that’s not the lens through which Nix viewed his performance on Sunday.

“Not going to lie it’s tough. You start getting in your head, start questioning … am I actually seeing it?” Nix said. “I feel like everybody goes through it, those who can get themselves out of it, finish the game and win … that’s usually when you find some maturity, some growth.

“It’s not the first time I’ve thrown three in a game … [but] hopefully it’s the last.”

Nix and the Broncos’ offense will have to move on quickly. They face the 8-6 Los Angeles Chargers on Thursday night at SoFi Stadium. Not only would the Broncos, who are currently in the No. 6 spot in the AFC playoff field, clinch a wild-card berth with a win, but they could put a little room between themselves and the Chargers, who are in the No. 7 spot and have a previous head-to-head win over Denver.

The first order of business heading into Thursday night is to re-settle Nix in an offense that has seen some struggles the past two games despite Denver winning both contests. Nix threw two interceptions in a 10-game stretch spanning Weeks 3 through 12 but has thrown five picks in the Broncos’ past two games.

Nix said Sunday one of the keys will be for him to avoid turning one mistake into multiple gaffes.

“I’ve got to be better … regardless that’s three [interceptions], you start feeling like every time I throw it is it going to get picked? You start having those mental thoughts, it’s challenging,” Nix said. “It’s probably the toughest part of playing the position … don’t let one turn into a false vision and see things that aren’t actually there.”

Nix’s performance on Sunday was the repeat of a pattern, as the interception that ended his first series set him up for a difficult day. That’s happened to him a few times already this season, most notably in Week 1 against Seattle — where an early second-quarter interception was the first of two he threw — and in Week 9 against the Ravens, as an interception he threw on the first play of the game set the stage for a 41-10 thumping by Baltimore.

For his part, Payton said some of the blame for Sunday’s struggles falls on him as the playcaller. The Broncos’ run game was ornamental at best, with just nine carries by the running backs in the first half and 49 yards rushing by three running backs in the game despite windy conditions that made passing tricky.

“I get mad at myself, couple of the calls I gave him,” Payton said. “He had one read that he knows better, but look it was just one of those nights when weren’t as efficient, especially against a zone defense like that … there were just few forced throws and a few dumb calls by me that I’ve got to be better.”

The Broncos and Nix must improve, as they face a tricky conclusion to their season. After the Chargers, the Broncos finish off with two more AFC opponents, Week 17 at Cincinnati (6-8) after a mini-bye and Week 18 against AFC West champion Kansas City (13-1). Both the Chargers (No. 7 in pass defense) and Chiefs (No. 13) will present challenges to Nix and the Broncos, at 5-4 in the AFC, need more conference wins for potential tiebreak scenarios.

Courtland Sutton smiled. P.J. Locke gasped.

Marvin Mims Jr. was given space on a crucial punt return in the fourth quarter against the Colts and all his teammates on the sideline knew something special was about to happen.

The second-year wide receiver — one of the best punt returners in the league — caught the ball on the far right side of Denver’s 25-yard line before sprinting to the left and down the sideline for a 61-yard return to Indianapolis’ 15.

Two plays later, quarterback Bo Nix threw a short pass over the middle to Nate Adkins that the second-year tight end turned into a 15-yard touchdown with a spin move and shake to give the Broncos a 17-13 lead with 13:51 to go.

It was the first blow landed in a 21-point fourth quarter Sunday at Empower Field at Mile Mile that gave the Broncos a 31-13 knockout victory and secured the team’s first winning season since 2016. And it all started with Mims in space.

“That’s why he’s the best returner in the entire NFL,” tight end Adam Trautman said.

The Broncos delivered an offensive performance to forget. Nix threw a career-high three interceptions, including two in the second quarter. They totaled just 72 rushing yards on 27 carries. And their third-down execution was a mess (6 for 17).

Denver needed someone to step up and ignite a spark. Mims turned out to be the guy.

The Oklahoma product averaged 32.3 yards on three punt returns. With 8:24 to go in the third quarter, Mims returned the ball 27 yards to the Colts’ 39-yard line. The Broncos, however, failed to capitalize, as Nix threw an interception to safety Nick Cross.

But when Mims gifted his team solid field position on his third return of the game, they took advantage.

“It’s like a gasp of air, like, ‘What is he going to do?’” Locke, Denver’s starting safety, said. “He’s dynamic. That’s all he needs is some space, man. I thought he was going to score twice, honestly. He keeps messing with us.”

For Mims, the key to being a successful punt returner is instinct. He said he has an idea of where to run the ball before stepping onto the field. However, there are moments when he has to change his direction in an instant.

Mims said the team’s ability to block down the field also contributed to his success.

“As punt returners, we are supposed to go left or right, but I never know where I’m going to go,” Mims said.

During the season as the Broncos have searched for ways to get Mims involved, the 2023 second-round pick has remained productive as a returner. He entered Sunday with 311 yards on 23 punt returns.

In the back half of the season, he has also made strides as a receiver. He has totaled 218 yards and two touchdowns on 12 catches in the last four games. But to beat the Colts and move the Broncos to within a win of their first playoff berth since Super Bowl 50, Denver needed Mims the returner. His 97 punt return yards against the Colts were a career-high.

“Him doing that, even if it’s 10 yards, is such a big momentum change for us,” Sutton said. “Watching him go down the sideline a couple of times today (was) exciting because at any moment you know that he could take it to the crib.”