The Steelers wasted little time finding a replacement for running backs coach Kirby Wilson, hiring the person Wilson will replace with the Minnesota Vikings — James Saxon. Saxon, who enters his 23rd season in the NFL as a player and coach, was the Vikings’ running backs coach the past three seasons. He was let go when head coach Leslie Frazier and his staff were fired after the 2013 season. The Steelers, however, could lose another assistant on their coaching staff. Defensive assistant Jerry Olsavsky, who spent nine years as a linebacker with the Steelers, is scheduled to interview this week with the Buffalo Bills about becoming their linebackers coach. Olsavsky has been a defensive assistant the past four years with the Steelers. The Steelers are seeking to improve their running game after going 22 games without a 100-yard rusher and averaging fewer than 4 yards per carry for the second year in a row. Their average last season — 3.5 yards, lowest in 10 years — does not, however, point out the impact rookie Le’Veon Bell had on the offense. Bell set a franchise rookie record for single-season total offense with a combined 1,259 yards — 860 rushing, 399 receiving — despite playing in only 13 games.