With rookies scheduled to take the field Wednesday for their first training camp workout, the San Diego Chargers reached a contract agreement late Tuesday night with first-round selection Sammy Davis, ESPN.com has learned.

The former Texas A&M star, the 30th player chosen overall, is expected to immediately challenge for a starting job at cornerback on a defense that statistically ranked last in the NFL against the pass in 2002. It is likely he will team with the Chargers' first-round pick in the '02 draft, cornerback Quentin Jammer. The Chargers are expected to announce the deal Wednesday, when Davis officially signs the contract.

Davis will sign a seven-year contract that totals $7.8 million and includes a signing bonus of $3.3 million. The deal can void to five years, provided Davis achieves certain playing time levels, and the five-year total is $6 million.

The signing bonus is higher than that awarded Green Bay linebacker Nick Barnett, who was taken one spot ahead of Davis in the first round. Barnett received $3.2 million in upfront money but also will earn a $150,000 roster bonus. Davis is just the seventh first-round choice to reach contract terms.

One of the fastest-rising defensive backs in the weeks preceding the draft, Davis has good size (5-feet-11¾ and 186 pounds), excellent quickness and well-developed techniques in coverage. His footwork is especially smooth; he moves fluidly to the ball; and he possesses good football awareness.

Twice during his college career, Davis won all-Big 12 honors, and he generally forced opponents to throw away from his right cornerback post.

In 39 games, Davis started 32 times, and he finished his college career with 188 tackles, 11 interceptions and 28 passes defensed. He also returned kickoffs on occasion.

Coming off the catastrophic 2002 season, the Chargers made upgrading their secondary a priority, and Davis was the first of three straight defensive backs chosen by San Diego with its top three selections.

Len Pasquarelli is a senior writer for ESPN.com.