With Mathews sidelined by a broken collarbone, the Chargers (1-0) ran 20 times for 32 yards in Monday's 22-14 victory at Oakland. Rivers settled for short passes - 30 of his 33 attempts went fewer than 20 yards - and completed 24 for 231 yards and a touchdown.
The four-time Pro Bowler did not commit a turnover, which is a good sign after he had 25 last season, including a career-high 20 interceptions.
"I've always tried to take care of the football and be smart but you have to be able to manage the situation," Rivers said. "... If you go back since I've been playing here and we don't turn the ball over, it's 90-something percent we win."
Since Rivers took over the starting job in 2006, the Chargers are 22-3 when they don't commit a turnover.
They are 36-11 during that stretch when allowing fewer than two sacks of Rivers, and he was sacked once Monday. Undrafted rookie left tackle Mike Harris had a strong game against the Raiders, according to coach Norv Turner, and could make a second straight start for Jared Gaither (back spasms). The team also signed guard-tackle Reggie Wells on Tuesday for depth.
As for Mathews, who rushed for 1,091 yards in 14 games last season, he has yet to be cleared for practice.
"We're continuing to evaluate him and hopefully it will be sooner than later," Turner said.
The only AFC team with fewer rushing yards in Week 1 than San Diego was Tennessee, which ran for 20 in a 34-13 home loss to New England.
Johnson had a career-low four yards on 11 carries. The Titans are hoping the former 2,00-yard back avoids a similar start to last year, when he was held to 366 rushing yards through eight games. They were 4-0 when he ran for more than 100.
Tennessee, though, will face a Chargers defense that held the Raiders to 45 yards on the ground in that unit's first game under coordinator John Pagano.
"We all know that the running game has to get better," said coach Mike Munchak, whose Titans had the league's 31st-ranked rushing attack in 2011. "We're not denying it. We're not trying to act like, 'Hey, we're OK.' We're not."
Neither is backup running back Javon Ringer, who has been in and out of the hospital for treatment on an infection in his left elbow.
Locker is questionable after hurting his left shoulder in the fourth quarter Sunday. Locker, who completed 23 of 32 for 229 yards with a TD and an INT in his first NFL start, had an MRI on Monday and is expected to split reps in practice with Hasselbeck this week.
Hasselbeck, who went 6 for 11 for 43 yards after Locker left, started all 16 of the Titans' games in 2011, but Munchak's plan is to give the eighth overall pick in the 2011 draft another start if he's healthy.
"If we still feel (Locker) can be productive, run around and do the things he needs to do to play the position, then we're going to be fine with him playing," Munchak said. "If for some reason he's not able to do those things, then we won't put him in a position that he shouldn't be in."
Locker or Hasselbeck could benefit from having Kenny Britt back from a one-game suspension following an offseason DUI, and fellow wideout Nate Washington should be good to go. Washington, who caught a 29-yard TD from Locker in the opener, suffered a bruised leg after a hard hit, but Munchak didn't think he had any concussion-like symptoms.
One player who missed the opener but should return Sunday for the Titans is defensive tackle Sen'Derrick Marks (knee), and that could help a unit which gave up 162 rushing yards in Week 1.
The Chargers, who went 5-3 at Qualcomm Stadium in 2011, have won four straight at home over the Titans organization and are undefeated in this series since a 27-0 loss at Houston on Sept. 27, 1992.