DENVER –The Broncos' best play of the afternoon didn't come without a cost.

Bradley Roby was on his to the end zone. The Broncos cornerback had reeled in an interception courtesy of Philip Rivers and was off to the races to give Denver its first touchdown of the afternoon.

But back on the Broncos' sideline, Chargers running back Melvin Gordon couldn't slow his momentum as he barreled off the field. Gordon bowled into Defensive Coordinator Wade Phillips, who fell back and hit his head on the tarp-covered grass.

"It was scary," outside linebacker Shane Ray said. "I came to the sideline. …  I didn't know what happened."

As the half approached and the Broncos regrouped, safety Darian Stewart said the team resolved to finish the game for their coach.

"We had to play for somebody," Stewart said, "and when that happened I knew he wanted to be out there. The most important thing for us was just going out there and getting this win for him."

And so the next-man up mentality extended past the players, just as it did two weeks ago against the Chargers when Special Teams Coordinator Joe DeCamillis filled in for Head Coach Gary Kubiak.

Linebackers Coach Reggie Herring assumed the play-calling duties for Phillips and rallied the defense, cornerback Bradley Roby said. The Broncos didn't look back from there as their defensive coordinator was evaluated at the hospital.

This wasn't the first time that Herring filled that role for Kubiak's staff. When Kubiak, Phillips and Herring were in Houston, Herring called the defensive plays when Phillips missed time with the team. On Sunday, Herring stepped up again.

"I'm really proud of him," Kubiak said. "I gave him a game ball. When it happened, I got on the headset a couple of times and he told me to shut the hell up and get off the headset. He did a good job. Reggie  is a fine coach. He's been a teacher for Wade for many years and he really stepped up and did a great job today."

Inside linebacker Corey Nelson, who filled in Sunday for the injured Brandon Marshall, may be the most qualified to speak on the job Herring did. Nelson was the defensive player who wore the helmet with the microphone inside, and as such, he had constant contact with his inside linebackers coach.

Wearing a helmet with a mic isn't a change for Nelson when he's in the game for Marshall, so the adjustment was seamless.

"It didn't affect me at all," Nelson said. "He's talking to me anyways. He's telling me 'All right, this is it. We've got to stop them.' So, it was nothing new. I was not surprised. I wasn't overwhelmed. I wasn't shocked. I just did what I had to do."

And on the sideline, Herring did the same.

As everyone from the defensive line to the linebacking corps to the secondary could attest, the transition to Herring as a playcaller was hardly a transition at all. Ray said Phillips and Herring are "the same person, pretty much."

"Reggie went out there [and] ran it like it was his defense with ease," Ray said. "No stress."

For as much as the players had to say about the job Herring did, Ray said the statistics speak even louder.

Under Herring, the defense gave up just one touchdown, picked off two passes and twice turned the Chargers over on downs. Despite the change in play caller, defensive end Jared Crick said nothing really changed for the Broncos.

"We have our same plays regardless," Crick said, "so we kind of kept to the same script that we would even with Wade. But Coach Reggie did a great job. He got the calls in early, got us set up, and we were able to do our jobs. So it was big for him to step in and do that for us."

In a close game, there wasn't really another option for the Broncos defense. They needed every big hit, every turnover and every fourth-down stop to come away with a win on Sunday afternoon.

With Herring at the helm and the players humming along as usual, Denver did just that. The defense's season hasn't been defined by injuries to Vance Walker, DeMarcus Ware, Brandon Marshall, Aqib Talib or any of the other players who have missed time.

The Broncos wouldn't let this define the season, either.