PITTSBURGH — The Pittsburgh Steelers head into the playoffs with one leg tied behind their back — running back Le’Veon Bell, the NFL’s rushing champ and the team’s MVP, likely will not play against the Baltimore Ravens on Saturday night at Heinz Field.

The Steelers moved quickly to add some protection when they signed veteran Ben Tate on Tuesday even though the injury to Bell’s right knee last Sunday showed no structural damage. Nevertheless, it was hyperextended, he was moving slowly around campus and they are not going to put him on a field six days after the injury if he is not close to the old Bell.

Coach Mike Tomlin noted on Tuesday that Bell was riding a stationary bike “training like he was preparing for the Tour” de France.

Was that a good sign?

“There won’t be any bikes on the field on Saturday night,” Tomlin answered.

A healthy Bell is a devastating two-way threat. He not only rushed for 1,361 yards, he added 83 pass receptions, 32 more than any back in franchise history. Now, the Steelers likely will start undrafted rookie Josh Harris, who was added from the practice squad with five games left and has only nine carries. Their only other running back, tiny rookie Dri Archer, has 10 carries.

Tate has a spotty resume that includes four teams in the past calendar year. He was cut last week by Minnesota, which claimed him off waivers after he was cut Nov. 18 by Cleveland. If Harris proves unworthy, they will turn to Tate quickly.

“I think a man rightly motivated and given time to prepare can do it in a number of days,” Tomlin said as to the readiness he can expect of Tate by Saturday.

They need some kind of running threat even if they do plan to ride quarterback Ben Roethlisberger, wide receiver Antonio Brown and their passing game on offense. On Nov. 2 at Heinz Field, that’s precisely what they used to trounce the Ravens 43-23. Roethlisberger threw for 340 yards, six touchdowns and no interceptions while the ground game produced just 55 yards.

The Steelers also believe they have a better defense these days, although not nearly as good as those from three or four years ago that dominated the NFL. Their secondary has improved as has their ability to come up with turnovers — two interceptions and a forced fumble by cornerbacks in last week’s AFC North-clinching victory against Cincinnati.

Their pass rush also has come alive recently with nine sacks in the past two games.

“They work hand in hand — rush and coverage. I’ll never deny that,” Tomlin said. “But I think to simply put it on (the pass rush) would be a disservice to the growth and development of those guys (in the secondary). They’ve done a nice job. They’ve created probably more opportunity for our rush as well. I think it’s a mutually beneficial relationship.”

SERIES HISTORY: Fourth postseason meeting, Steelers have won the previous three, all in Pittsburgh’s Heinz Field. They last met in a playoff game on Jan. 15, 2011, at Heinz Field, a 31-24 Pittsburgh win. The Steelers also won a playoff game in the 2001 season and the AFC championship game in the 2008 season. In the regular season, the Steelers hold a 21-17 advantage, including a 12-7 record in Pittsburgh. The teams split this year’s series, each winning by 20 points at home, both games played at night, as this one will be.

NOTES: SS Troy Polamalu (knee) and cornerback Ike Taylor (shoulder, arm), who each missed the last two games, went through a full practice on Wednesday. … Steelers QB Ben Roethlisberger was given the day off on Wednesday, which is standard when the team practices on the artificial turf indoors.