During a 2002 season in which the Detroit Lions' pass defense statistically ranked as the NFL's third-worst unit, the cornerbacks were regularly beaten deep, and there was a notable dearth of big plays.

The team addressed that deficiency early Saturday morning, signing unrestricted free-agent cornerback Dre Bly to a five-year, $24.5 million contract.

Bly, a four-year veteran who played his entire previous career with the St. Louis Rams, signed a contract that includes a signing bonus of $6.5 million and base salaries of $2 million (for 2003), $4 million (2004), $4 million (2005), $3.8 million (2007) and $4.2 million (2008).

Most teams had Bly, 25, rated as the top unrestricted free agent cornerback and the Lions wasted little time in pursuing him.

"We planned on being active and swift,'' Detroit coach Steve Mariucci said. "In looking for the best corner available, certainly Dre' Bly fits that description. He was our No. 1 targeted guy in free agency.''

"He turned things around in San Francisco a few years ago when they were in the hole,'' Bly said of Mariucci. "He got them to the playoffs and basically rebuilt the team. He didn't have the ability to bring in free agents but still, he rebuilt that team and got them to the playoffs. I just looked at it as a perfect opportunity for me to help this team. Coach Mariucci -- guys want to come in and play for him.''

Agent Brantley Evans flew into Detroit on Friday, even in advance of his client, and he and partner Ricky Lefft struck a deal that catapults Bly into an elite salary group.

Bly had rejected a four-year, $12 million offer from the Rams just before the start of the free agency period.

The former North Carolina star is a proven playmaker and, while he lacks the physical dimension (5-feet-9, 190 pounds) most teams covet, he is a very aggressive defender with more than sufficient strength. Blessed with better hands than many of the wide receivers in the league, and with great burst to the ball thrown in front of him, Bly will gamble on making the big play.

He was a second-round pick in the 1999 draft, played the first three seasons with the Rams as a "nickel" corner, and then became a starter last year. Bly has 14 interceptions and 48 passes defensed, with 154 tackles, for his career.

From an interception standpoint, his best season was in 2001, when he had six thefts. But even while his interceptions dropped to two in 2002, he had a terrific season in his first year as a starter, with 21 passes defensed.

Len Pasquarelli is a senior writer for ESPN.com. Information from The Associated Press was used in this report.