SAN DIEGO (AP) _ The San Diego Chargers retained their second key free agent in a four-day period Sunday, signing cornerback Dwayne Harper to a four-year contract believed to be worth $9.2 million.

The Chargers retained the rights to Pro Bowl wide receiver Tony Martin on Thursday by naming him their franchise player.

Harper, who joined the Chargers as a free agent in 1994 after spending six years with the Seattle Seahawks, was named San Diego's defensive player of the year in 1995.

But last season, after tearing his hamstring in the sixth week of the season, Harper missed 10 games. The Chargers finished 25th in the league against the pass.

``A hamstring injury is one of those things where you never can tell, but I feel good; I feel natural again,'' Harper said. ``There's been no pain. I'm ready to roll, and I'm looking forward to a strong season this year.

``It was very frustrating last year. I know one player can't make things happen for a team, but I think I could have helped our team a lot. If I could have played, we may have been in the playoffs.''

The signing of the 30-year-old Harper probably means the Chargers won't attempt to re-sign cornerback Darrien Gordon, a first-round draft pick out of Stanford in 1993.

Gordon averaged 14.9 yards per punt return last season _ second-best in the NFL.

The re-signing of Harper reunites the 10-year veteran with new Chargers secondary coach Rod Perry, who was an assistant with Seattle from 1989-91.

San Diego general manager Bobby Beathard said the club had an interest in Pittsburgh Steelers free-agent cornerback Willie Williams, but that it will no longer pursue Williams now that Harper has agreed to terms.

``I don't think any one player is going to make that much difference, unless it's your quarterback, but it certainly didn't help that we had Dwayne out of the lineup last year,'' Beathard said. ``There was nobody out there to give us the stability and leadership that Dwayne gives us. The togetherness we needed on defense just didn't seem to be there.''

Harper, who had not missed a start in six years prior to last season, had his best year in 1995 when he made 76 tackles and intercepted four passes, including three in one game against the Oakland Raiders.

``A week ago, I didn't think I'd be here,'' said Harper, who was being wooed by the Seahawks to return to Seattle. ``There was a good contract out there from Seattle, but this one was better. I wanted to stay here.''