SAN DIEGO (AP) -- Forget about Peyton Manning vs. Ryan Leaf when the Indianapolis Colts visit the San Diego Chargers on Sunday.

Leaf will be there, all right, but on the sideline _ wearing his cap forward, by the way _ relaying plays to Jim Harbaugh. Leaf can't play anyway, because he's still recovering from July shoulder surgery, so another matchup of the top two picks in the 1998 draft will have to wait for another year.

Manning vs. ex-Colt Harbaugh will be interesting, but it happened last year. Plus, Harbaugh is saying only nice things about his former team.

But there will be a matchup to really bang heads over. Colts running back Edgerrin James can become the first rookie to start his NFL career with three straight 100-yard games. Standing in the way are Junior Seau and his friends on San Diego's stingy defense.

This will be a much bigger test for the AFC West-leading Chargers than their 34-7 opening win at Cincinnati.

"If you run against us, our ego's hurt, definitely," Seau said. "That's bad. We just don't allow people to run on us."

To get the mark, James will have to do something only Denver's Terrell Davis has done recently against the Chargers. Since Davis went off for 187 yards on Nov. 30, 1997, the Chargers haven't allowed a 100-yard rusher in 20 games, the longest current streak in the NFL.

"We take pride in it," Seau said. "I'd be lying to you if I said it wouldn't hurt, because we have so much riding on it.

"The first thing we practice and preach is to stop the run. That's taught in minicamps and summer schools and training camp. When that's engraved in you, you have to take it to heart."

Seau and hard-hitting strong safety Rodney Harrison are the big names on San Diego's defense. Just as important are tackles John Parrella and Norman Hand.

"We have disciplined players up front and everyone's filling in the gaps," Seau said. "It's not a matter of who gets the tackle, it's just doing your job."

James, the fourth pick overall in the draft, rushed for 112 yards in an opening win against Buffalo and 118 in a loss at New England. His fumble against the Patriots set up Adam Vinatieri's winning field goal as New England rallied from a 21-point deficit.

James twice has fumbled while trying to get extra yardage.

"I ran for 100 yards in the last game and we still lost," James said. "I'd rather have had the win more than anything. If it happens, it happens. There will be other times when I'll have the chance to get other records, so I really don't care about it."

James also said he won't be awed by facing Seau, who recovered one Bengals fumble and forced another, which linebacker Gerald Dixon returned for a touchdown. "He's just another football player, because I'm trying to do my job and he's trying to do his. I've got to make plays against whoever is on the field. I can't worry about any one guy and make plays against him."

The rookie does know this about San Diego's defense: "They won't let up. That's one thing they do well the whole game."

James leads the AFC and is third in the NFL with 230 yards. San Diego is once again ranked No. 1 against the run in the NFL after holding the Bengals to 47 yards.

"Obviously we don't know much about the guy," Seau said. "If you would have asked me in the preseason who was going to lead the AFC, he wouldn't even be in the top five. So that's a compliment to him."

The Chargers have had bad luck with Colts rookie running backs before. On Dec. 31, 1995, Zack Crockett ran for 147 yards and two touchdowns as the Colts stunned the defending AFC champion Chargers 35-20 in a wild-card playoff game.

Then in his second season with the Colts, Harbaugh threw for two touchdowns and ran for another. The Colts' season would end one desperation pass short of the Super Bowl.

After two more seasons in Indy, Harbaugh was traded to Baltimore and the Colts drafted Manning. Manning and the Colts beat Leaf and the Chargers for their first win last year. Manning went on to set several rookie records, while Leaf was benched for poor play and bad behavior.

Harbaugh beat Manning and the Colts last year, rallying the Ravens from 10 points down in the fourth quarter for a 38-31 win.

Harbaugh said he has "great memories" of his four seasons with the Colts. "Some of the best times of my life came there. It doesn't mean I want to beat them any less, though," he said.

The Chargers are hoping their star running back, Natrone Means, will be recovered from a twisted left ankle and bruised right knee, and that guard Aaron Taylor is back from a sprained ankle. Leaf stayed home from practice Wednesday and Thursday with the flu, which several Chargers caught on the trip to Cincinnati.

INDIANAPOLIS Season schedule and results

SAN DIEGO Season schedule and results

September 12 Buffalo W 31-14 September 19 @New England L 28-31 September 26 @San Diego 4:05pm ET October 10 Miami 4:15pm ET October 17 @NY Jets 1:00pm ET October 24 Cincinnati 1:00pm ET October 31 Dallas 1:00pm ET November 7 Kansas City 1:00pm ET November 14 @NY Giants 1:00pm ET November 21 @Philadelphia 1:00pm ET November 28 NY Jets 4:15pm ET December 5 @Miami 1:00pm ET December 12 New England 1:00pm ET December 19 Washington 1:00pm ET December 26 @Cleveland 1:00pm ET January 2 @Buffalo 1:00pm ET

September 19 @Cincinnati W 34-7 September 26 Indianapolis 4:05pm ET October 3 Kansas City 4:15pm ET October 10 @Detroit 1:00pm ET October 17 Seattle 4:05pm ET October 24 Green Bay 4:05pm ET October 31 @Kansas City 1:00pm ET November 7 Denver 4:15pm ET November 14 @Oakland 4:05pm ET November 21 Chicago 4:15pm ET November 28 @Minnesota 1:00pm ET December 5 Cleveland 4:15pm ET December 12 @Seattle 4:05pm ET December 19 @Miami 1:00pm ET December 26 Oakland 4:05pm ET January 2 @Denver 4:15pm ET

Records source: STATS, Inc.

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