SAN DIEGO -- If you watch NFL games with regularity, you've likely seen the Nike commercial in which Chargers running back LaDainian Tomlinson is shown colliding with Pittsburgh safety Troy Polamalu.

The hit looks fearsome on your television set or iPhone, but here's the real story: The two never ran into each other during the filming sessions.

"What we did is we actually ran past each other so it looked like there was going to be a collision," Tomlinson said earlier this week. "Then they take the doubles and they say, 'OK, you guys hit,' and the guys go and hit each other."

Asked how many times the doubles hit each other, Tomlinson laughed and said "a bunch." So are you wondering what might happen if Tomlinson and Polamalu are running high speed toward each other in Sunday's game between the two teams? Let's just say it's unlikely there will be a direct hit.

"I don't expect it to be a shot like that," Tomlinson said. "If I see him, there's no way that I'm just going to run into him like that."

Ben's bad wing

Pittsburgh quarterback Ben Roethlisberger has been battling a shoulder injury during a recent three-game stretch in which he has been intercepted eight times and thrown just one touchdown pass.

But he said he has never considered sitting out to help the injury heal.

"It never was going to be an issue of me not playing," Roethlisberger said. "I was going to be out there no matter what. It's something that doesn't necessarily require surgery. It's just something you have to fight through."

What decline?

Steelers coach Mike Tomlin was amused to read newspaper coverage of the Chargers and find articles about a decline in Tomlinson's production.

Tomlinson has rushed for 629 yards -- the lowest nine-game output of his eight-year career -- but the yardage is still 11th best in the NFL.

"For a guy to have (over) 600 yards and you guys to be questioning his production is kind of funny to me," said Tomlin, who chuckled a few times before continuing. "He's only on his way to about 1,200 or 1,300 yards at this pace."

Et cetera

WR Craig Davis (groin) and CB Cletis Gordon (knee) did not practice Friday and have been ruled out of Sunday's game at Pittsburgh. Head coach Norv Turner said the team will make a decision on Sunday on whether or not to activate a player off the practice squad. … OLB Marques Harris (hamstring) was limited in practice and is questionable. S Steve Gregory (neck) was a full participant but is listed as questionable.

Contact staff writer Mike Sullivan at (760) 739-6645 or msullivan@nctimes.com. Staff writer Dan Hayes contributed to this report.