PITTSBURGH (AP) - The choice is never really much of a choice for Ben Roethlisberger.
Given the option to play or rest his badly sprained left ankle on Saturday against struggling St. Louis, the Pittsburgh Steelers quarterback would rather take the field regardless of the pain or the risk.
"I'm in the here and now," Roethlisberger said. "That's where we are coaches and players and a team."
Then again, Roethlisberger allowed, it's never his call.
"That's a coach's decision, as always," he said.
And coach Mike Tomlin decided to go with veteran backup Charlie Batch.
A playoff spot already clinched, the Steelers (10-4) will try to keep their hopes for an AFC North title alive with Batch, who is 4-2 as a spot starter over the last six seasons.
Yet they allow they'll approach the game differently if Batch is under center. Offensive coordinator Bruce Arians typically comes up with two game plans, one for Roethlisberger and another for the 37-year-old Batch, just in case Roethlisberger can't play.
On Saturday, it's time for Plan B.
Though he lacks Roethlisberger's big-time arm, Batch can still get it done. He went 1-1 last season while filling in as Roethlisberger served a four-game suspension for violating the league's personal conduct policy.
"We can still make big plays with (Batch)," wide receiver Mike Wallace said. "But instead of catching the ball 50 yards down the field, maybe we do it 15 yards down the field and do stuff after the catch."
And with Roethlisberger's ankle limiting his ability to get out of the pocket, Batch gives the Steelers more flexibility in playcalling.
Though he passed for 330 yards in a 20-3 loss to San Francisco, Roethlisberger acknowledged the 49ers quickly figured out what was coming depending on how the team lined up. If he was under center, it was a run. If he was in the shotgun, he was going to sling it.
"I honestly think that's probably why they deferred when they won the toss," Roethlisberger said. "They were going to come after me."
St. Louis certainly figured to do the same with defensive end Chris Long and his 13 sacks leading the way. Instead Long will chase down Batch or third quarterback Dennis Dixon.
"(Batch and Dixons) are certainly more mobile," St. Louis defensive coordinator Ken Flajole said. "They have a little bit more scrambling ability. Ben does a great job of getting away from pressure, but that ankle I'm sure has been a problem for him."
Roethlisberger doesn't necessarily agree. Despite throwing the ball 44 times in San Francisco and taking a handful of shots in the process, the two-time Super Bowl winner wanted to play against the Rams even if he was "five percent" even if it adversely affected his team's postseason chances.
"I don't go out there worrying about playing with an injury," he said. "I don't go out there worrying about getting hurt worse."
Now he won't have to, making Saturday a battle of the backups.
St. Louis quarterback Sam Bradford, didn't practice this week and appears likely to miss his fifth game of the season with a sprained ankle of his own.
Still, like Roethlisberger, Bradford would prefer to be on the field. It's why he refused to be placed on season-ending injured reserve even if the Rams are putting the finishing touches on an eighth consecutive non-winning season.
"It's my job, that's why I'm here," Bradford said. "I'm here to play football, I'm not here to ride the bike, I'm not here to sit on the sideline."
Yet the Rams will be heading to the sideline regardless when the season ends on New Year's Day. Not the Steelers, who have designs of collecting a record seventh Lombardi Trophy.
To get to a ninth Super Bowl the team needs Roethlisberger as healthy as possible and there's no better treatment for a bum ankle than rest.
"I think if you rest, you obviously can hopefully improve and get yourself to a higher percentage but I like to be out there," Roethlisberger said.
Regardless of who is under center, the Rams are hoping to give embattled coach Steve Spagnuolo a much-needed lift.
St. Louis is 10-36 in Spagnuolo's three seasons and taken a significant step back this year after going a respectable 7-9 in 2010.
A steady stream of impact players to the injured reserve list hasn't helped. The Rams are the league's most anemic offense, though running back Steven Jackson is 34 yards away from posting his seventh consecutive 1,000-yard season.
The streak is a testament to Jackson's toughness, durability and patience. St. Louis hasn't made the playoffs since his rookie year in 2004.
He believed then a trip to the postseason would become an annual event. It has not, and there's a chance the Rams will blow it up and start all over again next year.
It's one of the reasons Jackson has so much respect for the Steelers.
"This team historically is one of the elite, year in and year out," Jackson said. "They seem to always put a team together that's playoff worthy."
This year's group is no exception, even if the Steelers have only been dominant in small spurts. That's fine by them. There's still a chance to get it going, preferably with their franchise quarterback healthy.
"We're not concerned with that people are saying or what other people are doing outside of the building," safety Troy Polamalu said. "I will say this, the team that may win the Super Bowl lost their last game, so we'll see."