Eli Manning and Philip Rivers will forever be linked by the draft-day trade in 2004 that brought Manning to the New York Giants and Rivers to the San Diego Chargers.

This season, they may end up being linked for leading a pair of contenders that underachieved.

The quarterbacks meet for the first time Sunday at Giants Stadium, with Manning looking to help New York avoid a fourth straight loss and Rivers trying to lead the Chargers to their first victory over a winning team.

San Diego (4-3) took Manning with the first pick in the 2004 draft, even though his family told the Chargers not to select him days before. After they selected him anyway and the Giants (5-3) chose Rivers at No. 4, the Chargers sent Manning to New York for Rivers and picks that San Diego used on linebacker Shawne Merriman and kicker Nate Kaeding.

The trade seems to have helped both clubs. Manning was the Super Bowl MVP two years ago when the Giants upset the 18-0 Patriots - the team that knocked off Rivers and the Chargers in the AFC championship game. Both players have been to one Pro Bowl.

"It's fun," Rivers said Monday. "The one thing I know and I know Eli knows, all the quarterbacks know, we're not playing one another out there. We've got plenty of other things to worry about on the defensive side of the ball we have to go against.

"But it is fun competing against another team led by a quarterback that you are linked to in many ways, especially being the same draft class."

Rivers backed up Drew Brees the last time these teams met - a 45-23 Chargers win Sept. 25, 2005. Manning was booed throughout his first game in San Diego, but completed 24 of 41 passes for 352 yards and two touchdowns.

Manning would likely settle for a similar effort, considering what he has produced during the Giants' slide. He had 10 touchdowns and two interceptions in New York's 5-0 start, but threw three TDs and six interceptions over the last three games.

"There is no secret ingredient," Manning said. "There is no 'We have to change our philosophy.' There is none of that. We are not in panic mode right now. But we do need to get better and we do need to play better than what we are playing right now. This is going to be a big week for us, this week versus San Diego, and hopefully we get back on track."

While Manning has played poorly the last three weeks, New York's defense has been worse. The Giants were outscored 112-61 during that span, with opponents totaling 1,172 yards.

New York allowed 180 rushing yards for the game and 30 first-half points in a 40-17 loss at Philadelphia on Sunday. The Giants' last four-game losing streak came Nov. 12-Dec. 3, 2006.

"I don't know what has happened to us the last three weeks," defensive end Justin Tuck said. "That's kind of disheartening, but it lets me know the guys care. You can just tell that frustration is kind of boiling over."

The defense should get some help this week, with defensive tackle Chris Canty and weakside linebacker Michael Boley expected to play.

Canty has been sidelined since the opening game with a calf injury. Boley had surgery on his right knee last month.

All of San Diego's wins were against losing teams, with its defeats coming to contenders Denver, Baltimore and Pittsburgh. The Chargers' two straight victories came against lowly Kansas City and Oakland - teams that also account for two of New York's wins.

"Every week is a treat to play in the NFL, to play in an NFL game," Rivers said. "But these are the kind of games, the reason why you play. You get to go right in the thick of all the action in the East Coast, being in New York, and play, obviously, a team that won the championship two years ago and is a very capable one and thought of highly this year.

"It's a tough place to go on the road, in a game I think that will say a lot about us."

San Diego limited Kansas City to 203 yards in a 37-7 road victory Oct. 25 and held Oakland to 180 yards in last Sunday's 24-16 win. The Chargers know it will be more difficult against a Giants offense that is fifth in the league with an average of 386.9 yards.

"We are growing and we're getting better," coach Norv Turner said. "We're getting some guys going. We'll have a great week of practice and we're looking forward to going back and playing."

The Giants rank 19th against the run, but will face a Chargers rushing attack that is second worst in the league with 523 yards. LaDainian Tomlinson ran for 192 in the 2005 game against New York, but has gone a career-high 13 straight games without gaining 100.