The Carolina Panthers took a huge step toward strengthening the front four of their defense Tuesday, signing veteran free agent defensive tackles Darwin Walker and Ian Scott.

Walker's signing was expected. The addition of Scott solidifies what will likely be a four-man rotation at the position, along with holdovers Maake Kemoeatu and Damione Lewis.

"We had a chance to get two veteran defensive tackles," Panthers general manager Marty Hurney said.

"You bring experience and talent into the mix with both of them."

Both players battled injuries last season, but passed their physicals.

Walker (6-foot-3, 294 pounds), who will be 31 in June, had knee and elbow injuries last season. He has 28.5 career sacks and has had six or more in three seasons.

Sacks are much harder for inside players to accumulate than for defensive ends.

"Darwin has the ability to rush the passer; he's a very good player inside," Hurney said.

Scott, 26, has good size as well at 6-3 and 302 pounds. He played in 49 games with 33 starts with Chicago from 2003 through 2006.

He was signed as an unrestricted free agent by Philadelphia last year, but was placed on injured reserve before the start of the season because of a knee injury.

A fourth-round draft pick in 2003, Scott had 155 tackles, two sacks and one interception with the Bears.

"Ian's a guy we have always liked," Hurney said. "We had been talking (with his agent) for some time."

Part of Carolina's lure for both players was being able to play closer to home. Walker is from Walterboro, S.C., and Scott is from Greenville, S.C.

Defensive depth chart

The addition of veteran defensive tackles Darwin Walker and Ian Scott on Tuesday addresses an area of need for the Panthers.

DT Maake Kemoeatu Ian Scott Nick Hayden
DT Damione Lewis Darwin Walker
DE Julius Peppers Stanley McClover
DE Charles Johnson Tyler Brayton Hilee Taylor
MLB Jon Beason Dan Connor Landon Johnson Adam Seward
SLB Thomas Davis Adam Seward J. Anderson Tim Shaw
WLB Landon Johnson Na'il Diggs Dan Connor
CB Ken Lucas Richard Marshall
CB Chris Gamble Ricardo Colclough Dante Wesley
SS Chris Harris Nate Salley
FS Charles Godfrey Terrence Holt