Ryan Mathews would return to the sideline later -- he jogged out from the training room -- but the Chargers declined to insert their heralded youngster into the game.
So with the NFL not forcing the Chargers to reveal his condition until Wednesday, the Chargers are going to do just that.
"He's sore," coach Norv Turner said. "He wanted to go back in the game, but I didn't think it was appropriate. I didn't want to turn it into a longer injury. We'll see how it goes on Wednesday."
And with that, Chargers fans will just have to trust that everything will be fine with Mathews, who was brought in to resurrect a horrible running game. That running game is doing just fine, but more so because Mike Tolbert came in for Mathews Sunday and rushed for two touchdowns.
Mathews, though, through Twitter, is telling folks he's fine. Although he has said he could skip Wednesday's practice to save himself for Sunday's game in Seattle.
What he really has to do is save himself from giving up the ball. In two games, he's lost the ball twice, which has resulted in 10 points for the Chargers' rivals.
"We have some work to do in terms of taking care of the football," Turner said. "When you're young, guys want to pull the ball away from you. There's an extra effort with a rookie. He just has to continue to work to protect it.
"He was great taking care of the ball in training camp. (Sunday), he thought he was down and he relaxed at the end of the play."
Before the fumble, Mathews averaged 5.2 yards per carry and had 55 yards of offense in less than a quarter.
"Ryan was off to a great start and what we believed was going to be a very big day," Turner said. "He was running well and caught a few passes out of the backfield. It was nice see him more relaxed than he was a week ago."
But will we see him this week? Stay tuned.
If not, the bruising Tolbert proved he is up to the challenge of being the lead back.
--The team declined to update any of their injuries, including RB Ryan Mathews' sprained ankle and how OLB Shawne Merriman's tender Achilles' tendon held up.
--Coach Norv Turner said he wasn't tempted to insert RB Ryan Mathews back into the game after he left in the first quarter with a sprained ankle. Turner said he didn't want a one-week injury turning into a six-week injury. Plus, Mike Tolbert was killing the Jaguars. Mathews said he could have returned. "I feel like I could have (returned)," Mathews said. "But the coaches didn't want to risk anything."
--Tolbert, at 5-9, 245 pounds is a load and kind of a hybrid. He started as a fullback and has morphed into a running back. Wonder what kind of mileage he gets? "About 7-10 miles per gallon," he said. "It depends on the play."
--TE Antonio Gates said the Chargers running backs' play is paying dividends for the pass-catchers. "They were able to give us such a lift offensively and that's what sprang the passing game,' he said. "It gave us an opportunity to make plays in the passing game."
--Turner is a bit testy about the lack of credit LT Brandyn Dombrowski is getting in replacing unsigned Pro Bowler Marcus McNeill. "We give (Dombrowski) someone else's number and you guys would be raving about how he's playing," Turner said.
--The Chargers didn't sell out their home opener, breaking their 48-game streak to force a local TV blackout.
--QB Philip Rivers threw for three touchdowns and over 300 yards in a pretty solid effort. He did have two interceptions -- he has never had a three-interception game in the NFL -- but both passes were tipped by their intended receivers.
--RB Ryan Mathews seems confident he will play Sunday despite suffering a sprained ankle. Mathews is off to a decent start, but has had issues with ball security.
--RB Mike Tolbert was a stud in moving the pile and even occasionally finding the edge in rushing for two touchdowns and 82 yards. Tolbert has morphed from a fullback to a running back and is showing he can be more than a short-yardage back.
--TE Antonio Gates is on fire as he proves when he's healthy, few can hang with him. Despite being the Chargers' most reliable pass-catcher, he was left wide open twice for touchdowns. Gates' second scoring catch moved him into a tie with Shannon Sharpe for the second-most touchdowns all-time at 62.
--WR Malcom Floyd is stretching the field in place of Vincent Jackson; Floyd and Rivers have always shared a strong connection. Floyd had three catches for 95 yards, including a 54-yarder for a touchdown.
--WR Buster Davis is showing that just maybe, he's not a first-round bust. Davis has done little in his Chargers career but he's getting more chances with Jackson's absence. Davis had five catches for 48 yards.
--WR Legedu Naanee is supposed to be a viable threat, but he had but one catch for 14 yards. But in the Wildcat formation, he took a direct snap before heading off.
--RB Darren Sproles seemed to have that extra quickness which was missing in the slop of Kansas City. Sproles is such a valuable weapon and he proved it Sunday with 37 rushing yards, 63 receiving yards and 56 return yards.
--ILB Brandon Siler filled in for the injured Stephen Cooper (knee) and the defense didn't miss a beat. Funny, though, that Siler is regarded as a physical run-stopper, but he managed an interception and a thunderous hit on David Garrard which forced an interception.
--CB Antoine Cason might have had his coming out party -- the Chargers hope so. The former first-round pick who won a starting job in camp had two interceptions and forced a fumble -- all in the first half. A big dose of confidence was gulped by Cason after this performance.
--ILB Kevin Burnett was derailed by injuries most of last year but he is fit this year and he proved it again Sunday. Burnett had an interception and fumble recovery to go with five tackles.
--ILB Stephen Cooper (knee) isn't expected to practice Wednesday and could be down for a second straight week.
Should the Chargers rest Ryan Mathews? Discuss inside the message boards.