49ers sign Ravens DT Aubrayo Franklin

Defensive tackle Aubrayo Franklin signed a three-year contract with the San Francisco 49ers on Saturday, the third free agent in two days to bolster one of the NFL's worst defenses last season. The 49ers also re-signed Bryan Gilmore, their third receiver last season.

Franklin spent his first four NFL seasons with the Baltimore Ravens, where he played with 49ers coach Mike Nolan as his defensive coordinator for two years. Franklin hopes to be San Francisco's starting nose tackle, and he believes he's joining Nolan's club at the right time.

"I didn't keep up with them last year, but my agent was telling me that Coach Nolan wants to run a true 3-4," Franklin said. "I have a good relationship with Coach Nolan. He drafted me."

Though Franklin has just one sack and 40 tackles in his four-year career, Nolan believes he can be the space-filling nose tackle San Francisco lacked last season, essentially forcing the coach to scrap his preferred defensive scheme.

"Aubrayo is an aggressive, physical lineman that fits the description of a prototypical nose tackle in a 3-4 defense," Nolan said. "He brings tremendous value to our football team."

At the least, Franklin should be a capable replacement for defensive tackle Anthony Adams, who's expected to leave after struggling to fit into a 3-4 scheme.

On Friday, San Francisco signed former Buffalo cornerback Nate Clements to an eight-year, $80 million contract, then signed former Philadelphia safety Michael Lewis to a six-year deal.

All three players should be significant upgrades for a defense that allowed an NFL-worst 412 points last season, leading to defensive coordinator Billy Davis' firing.

Franklin is the latest of several former Baltimore players to follow Nolan to San Francisco. Franklin will play alongside defensive end Marques Douglas, who spent five of his first six NFL seasons with the Ravens.

But the 49ers failed to land Baltimore linebacker Adalius Thomas, thought to be one of their top targets along with Clements. Thomas, a Pro Bowl player last season, signed with the New England Patriots on Saturday.

Gilmore caught just eight passes for 150 yards last season, but San Francisco is short on depth at receiver after cutting troublesome Antonio Bryant on Thursday night.