Updated

By Mark Lamport-Stokes

(Reuters) - Philip Rivers and the San Diego Chargers, perennially viewed as likely Super Bowl contenders only to fade at crucial moments, aim to resurrect a frustrating 4-4 season when they host the Oakland Raiders on Thursday.

After making an encouraging 4-1 start to their 2011 campaign, the Chargers lost twice on the road before being beaten 45-38 at home on Sunday by the Super Bowl champion Green Bay Packers.

They are tied at the top of the AFC West with the Raiders and Kansas City Chiefs but know they need to improve their consistency and mental toughness, especially in the late stages of games, if they are to win a division they once used to own.

"We have a lot of great character in this locker room and we'll continue to fight," Chargers cornerback Quentin Jammer told reporters while his team prepared for their ninth game of the season.

"Four and four, we've been here before. We'll continue to fight and we'll see where we're at after it's all said and done."

Though the Chargers lost their third straight game on Sunday, Jammer was proud that he and his team mates fought back from a yawning 45-24 deficit in the final quarter to give the unbeaten Packers a fright.

"You always feel better when you see your team fight and rally and scratch and claw to get back in the game and have the opportunity to tie and the opportunity to win," he said.

"I'm not happy with the loss but I am happy that I saw my guys fight to get us back in the game."

The Chargers, who led the National Football League in total offense and defense after the 2010 regular season, have dropped to sixth in offense this year and to seventh in defense.

Rivers, who swiftly established himself among the game's elite after taking over as quarterback in 2006, has been one of his team's most reliable performers -- until this season.

Though he lies fifth in passing yards with a total of 2,469, he leads the league with 14 interceptions and 17 turnovers overall and languishes 20th in the all-around quarterback rankings.

Nine days ago, he fumbled a snap with a little over a minute left in the fourth quarter and his team in position to kick a game-winning field goal against the Chiefs before they lost 23-20 in overtime.

On Sunday against the Packers, Rivers threw two interceptions in the opening quarter, each of them leading to touchdowns, to hand Green Bay a decisive advantage.

GAME CHANGER

"Obviously, you can't turn the ball over," Rivers said after also throwing four touchdown passes on Sunday to match his career-best. "That was the difference in the game.

"That's something I need to keep working on and do a better job of. We gave ourselves a chance and never quit, but there's no consolation when you lose."

Oakland's Carson Palmer, who will be River's opposite number on Thursday, expressed deep sympathy with his fellow quarterback on a conference call this week.

"When you watch another quarterback go through what he went through ... your heart goes out to him," Palmer said. "Those things are just freak accidents.

"Any quarterback could be in his shoes. Regardless of statistics, if you've got a chance to win your division or be in first place in your division, that's all you can ask for.

"Of course you want to be perfect and win every game, but that very, very rarely happens and he's put his team in a position to be playing for first place."

Rivers, who has started every game for the Chargers since 2006 and led the team to a stunning 14-2 record in his first season, knows the Raiders will provide a tough physical challenge on Thursday.

"It's going to be all you can imagine," he said. "We haven't beaten these guys since '09. We lost both games against them last year and obviously that had a big impact on us not making the postseason."

The Chargers failed to win the AFC West in 2010 for the first time in five years.

"We've got an eight-game season that starts on Thursday night," Rivers said of San Diego's remaining schedule in the regular season.

"Three teams are deadlocked in the division and Denver's (Broncos) spotting us all a game. All four teams are alive. We'll see what happens."

(Editing by Rex Gowar)