RENTON, Wash. — Nationally, it’s a rematch of Super Bowl XLVIII, a battle of two teams expected to contend to get back there again this season.

But for the Seattle Seahawks, the greater importance of Sunday’s game against the Denver Broncos is getting back on the winning track after a surprising loss at San Diego.

The Seahawks simply didn’t play very well against the Chargers, with eight penalties, a costly turnover, and numerous missed tackles and blown blocking assignments. It added up to the first loss by more than a touchdown since October 2011 when quarterback Russell Wilson was still at the University of Wisconsin.

And it left a team that has become known for its youthful enthusiasm and boisterousness uncommonly subdued.

And tired. Truth be told, it might be said that the Seahawks just couldn’t take the heat, which cornerback Richard Sherman described as “120 degrees” in San Diego and said he had to pour ice over himself and took intravenous fluids.

In perhaps further evidence of the effects of that game, running back Marshawn Lynch, who carried only six times, sat out practice Wednesday with a back injury. He left the game early Sunday when his back tightened up. However, nothing has been said to indicate he won’t play Sunday.

“Really serious,” coach Pete Carroll said Wednesday of the team’s mood this week. “And these guys, they are clued in that they want to put together a really good week right now. We know that we a have a terrific championship matchup coming up. But it’s more that they want to play really good football. And I’m sure I’m going to see that all during the week.”

Sherman said, “Guys are just locked in. When you feel like you lost a game, you feel you shouldn’t have lost, guys are going to feel some type of way. They’re just ready to execute, ready to get back on the field.”

Sherman said it doesn’t hurt that the opponent is an unquestionably good team in the Broncos, who had set a NFL record for points scored in a season with 606 before being shut down by Seattle in the Super Bowl, 43-8.

“I think that they want to come in and get a win,” Sherman said. “That’s the same motivation that we have.”

Sherman, though, downplayed the idea that what happened in the Super Bowl will hover much over Sunday’s game.

“Not even all the guys that are playing in this game were there last year so I’m not sure all the guys are motivated that way, 43-8,” he said. “I think they’re just motivated to win.”

Certainly, Seattle’s defense is after allowing 30 points for the first time since a 30-28 loss in the divisional playoffs to Atlanta in 2013 and giving up 377 yards.

San Diego’s outburst has Seattle in some uncommonly mediocre territory in the NFL defensive standings. Seattle’s 23 points allowed per game, for instance, ranks 20th and the 225.5 passing yards allowed per game is 18th.

“I don’t think we felt like we played like we can,” Carroll said of the defense. “So they are really anxious to bounce back and show a really good game.”

The game also continues something of a gauntlet of great quarterbacks for Seattle to open the season, first facing Green Bay’s Aaron Rodgers before getting San Diego’s Philip Rivers last week and now Denver’s Peyton Manning.

“It doesn’t get any better than this,” Carroll said. “They can ship New England in here somewhere in the bye week if they want. It’s as hard as it can get. It’s great for us; it’s going to help us during the course of the season. You can’t get any better challenges than these guys throwing the football. Aaron (Rodgers) is phenomenal, look what we just saw (Philip Rivers), and here comes Peyton (Manning).

“We haven’t talked about it that much openly because we look at one game at a time, but now that we’re at the third one of these, it’s a great stretch for us and it’ll only help us. We have to be so on the mark and so on with everything that we’re doing to defend these guys that it’ll help us.”

A lot was made of Sherman giving up four completions against the Chargers after not having a single ball thrown his way against the Packers.

Carroll said he thought the game Sherman had against San Diego was “pretty normal. … I think it’s amplified by the fact that the first week, the ball didn’t go his way at all. They just played normal football and a couple of plays went that way and he defended some stuff and they got a couple of balls. But that is totally going to happen.

“I thought that the San Diego guys were on point with it. You heard Philip Rivers talk about it, they just played a regular game plan and showed respect for the player that Richard is and it worked out pretty normal, I think.”

Carroll said Marcus Burley will cover Denver’s Wes Welker in the slot and that the Seahawks assume Welker will “be out there a lot” now that his NFL suspension has been reduced and he is free to play this week. Burley was acquired in a trade with Colts before the first game and has emerged as the starting nickel with Jeremy Lane on IR-designated to return with a groin injury.

NOTES: S Kam Chancellor (ankle) sat out practice Wednesday. … TE Zach Miller (ankle) missed practice Wednesday. … RB Christine Michael (hamstring) was a limited participant Wednesday. … LB Kevin Pierrie-Louis (hamstring) may rejoin the team this week.