"On this surface," said Parker, "all that cutting won't be effective."
Sproles will play tailback in place of LaDainian Tomlinson, who finally admitted to reporters Wednesday that his groin tendon "is definitely torn."
The Chargers still list Tomlinson as doubtful, but he'll miss his second consecutive AFC Championship Game with an injury.
Last week, Tomlinson carried five times for 25 yards and a touchdown, while Sproles, the 5-foot-6, 181-pounder, became the star of the overtime win over the Indianapolis Colts. He carried 23 times for 105 yards and two touchdowns and also caught five passes for 45 yards.
It was Sproles' second consecutive 100-yard game. He'd rushed for 115 yards on 14 carries the previous week against the Denver Broncos. His only other 100-yard game came in 2007 against the Detroit Lions. Sproles set 23 school records as a running back at Kansas State, but since being drafted in the fourth round of the 2005 draft he's been used primarily as a return man in the NFL ... until now.
"That cutting and quickness and all that, it's great," Parker said. "But I don't think he's going to like it here."
Parker has rushed for 213 and 223 yards in games at Heinz Field, but said it takes experience to get a feel for the running surface.
"I've played on it enough to know when to cut and when not to," he said. "It really does take some getting used to."
WEATHER ON THEIR MINDS
The Chargers played in snow and a 26-degree wind chill factor at Heinz Field on Nov. 16, and apparently it bothered them.
The Chargers have requested to bring along their own generator to Heinz Field in order to provide adequate warmth on their sideline in what the National Weather Service predicts will be 20 to 27-degree weather.
The Steelers have never fielded such a request, but are expected to relent. That background may explain Coach Mike Tomlin's response Thursday to a question about the weather.
"Weather's not going to be an issue," Tomlin said. "We are in the divisional round of the playoffs. If anybody is concerned about the cold, there's a strong chance they're going to go home."
EARLY ARRIVAL REQUESTED
The Steelers request that fans arrive early to Heinz Field to avoid logjams at the entrance gates near kickoff (4:45 p.m.).
To that end, the Steelers scheduled the corporate 1980s rock band Styx to sing the national anthem, followed by a military flyover.
Styx will attempt to sing at 4:30 p.m., followed by player introductions. The coin toss with honorary co-captain Jerome Bettis will occur at 4:40 p.m.
Gates A and B will open at 1:30 p.m. and Gate C will open at 2:30 p.m. Fans can shop at the merchandise store, peruse the Great Hall, or watch the NFC playoff game on the scoreboard.
The Mystic Knights, a real rock band, will perform before the game in the West Main concourse.