The Sports Xchange

PITTSBURGH — One of the main concerns in the spring for the Pittsburgh Steelers is to rebuild a defense that has fallen way off the dominant forces they had for much of this century.

Linebackers coach Keith Butler replaced longtime defensive coordinator Dick LeBeau this year and he will be forced to count on plenty of youngsters to come through for him, albeit those with strong college resumes.

They include two first-round draft picks at linebacker, Jarvis Jones on the right outside and Ryan Shazier on the inside. Both were hurt last season but showed some promise beforehand. There also is cornerback Cortez Allen, who signed a five-year, $26 million contract before last season and then was benched for poor performance halfway through it.

There is more. Stephon Tuitt will open his second season as their starting left defensive end. Rookie Senquez Golson, their second-round pick, could wind up playing in their nickel defense. Shamarko Thomas, entering his third season, will try to replace Troy Polamalu at safety. The Steelers traded a third-round draft pick in 2014 in order to draft him in the fourth round in 2013, but he has been hurt and disappointing so far.

Butler does not have many old hands left — linebacker Lawrence Timmons made his first Pro Bowl last season and linebacker James Harrison came out of retirement early last season to help out and returned for another.

The Steelers had some of the NFL’s best defenses through much of the past 15 years but fell off drastically the past two seasons. There is new blood everywhere, including the coordinator, who would like to stop the bleeding.