The Oakland Raiders concluded a three-day mini-camp on Saturday, and for starting defensive end Regan Upshaw, the weekend session unfortunately signaled the end of his 2002 season.

	Upshaw

Raiders rookie coach Bill Callahan confirmed that Upshaw, the team's leading sacker in 2001, will miss the entire season after an MRI exam revealed a torn anterior cruciate ligament in his right knee. It is not yet certain when Upshaw will undergo surgery, although it is tentatively scheduled for next week, but he will spend all of 2002 on injured reserve.

"I'll be back, but not for a while, I guess," said Upshaw, a six-year veteran who has played in Oakland the past two seasons. "When they first tell you, it kind of leaves you speechless, even if you were expecting the worst. Yeah, it's a setback, but I'm going to come back better than ever. This has become my biggest challenge now. I've got to be a man on a mission."

The injury occurred during a Thursday drill, when Upshaw's cleats caught in the turf, and was originally believed to be just a sprain. But further examination revealed the tear. Such injuries typically require a rehabilitation period of six to nine months.

The loss of Upshaw certainly magnifies the depleted nature of the Oakland defensive front. End Trace Armstrong is still recovering from an Achilles injury that sidelined him for most of the 2001 campaign and his work may be limited in training camp. But even if healthy, Armstrong's age precludes him from being a full-time player at this point in his career.

Oakland lost both of its starting tackles -- Darrell Russell to a year-long suspension for a repeat violation of the NFL substance abuse policy and Grady Jackson in free agency -- from the 2001 season. The club signed tackles John Parrella and Mike Mohring in free agency and, with holdovers Rod Coleman and Chris Cooper, should be able to get by at the interior position.

The Raiders are perilously thin at end, though, and the loss of Upshaw removes a player who arguably is the team's best outside pass rusher. The Oakland personnel department is always resourceful in finding players, but the free agent pool has been depleted at end, and young veterans like DeLawrence Grant and Emil Ekiyor might have to step up.

"It's just one of those freak, unfortunate things," Callahan said.

Upshaw becomes at least the fourth player this offseason to be lost for the entire 2002 campaign because of a knee injury.

The club also will be penalized on its cap because it will have to carry Upshaw, who has a base salary of $1.45 million and a cap charge of $1.916 million. Oakland is about $2.22 million under the spending limit, but needs most of that room to sign draft choices, and won't have much left over to sign a veteran.

One possibility is that the Raiders will use rookie linebacker Napoleon Harris, the second of their two first-round draft choices this year, at a rush-end position. The former Northwestern star played the entire 2001 season, in fact, at end because of injuries at the position.

Upshaw, 26, started 15 games in 2001 and had 31 tackles and seven sacks. Although he is known to take bad penalties at times, when he allows his emotions to get the better of him, the Raiders coaches like his passion.

The former University of California star began his career in Tampa Bay, as a first-round choice in 1996. He was traded by the Bucs to Jacksonville during the 1999 season and then signed with Oakland as a free agent in 2000. For his career, he has played in 86 games and started 69 of them. Upshaw has posted 142 tackles, 31½ sacks, four forced fumbles and one interception.

Len Pasquarelli is a senior writer for ESPN.com.