Though the Pittsburgh Steelers have listed quarterback Ben Roethlisberger as "day-to-day" on the injury report, it's likely that he'll be in action on Sunday. He does have an ankle sprain, stemming from his most recent game against the Cleveland Browns, but he's had plenty of time to rest so far - having the most resting time possible outside of a bye week with his last game being on Thursday Night Football and his next game coming on Monday Night Football.
On top of that, Roethlisberger has always been a very tough quarterback, capable of recovering quickly from injury and playing through the pain. He even went into the game against Cleveland after suffering the injury and played through the pain. He's always been a guy who could absorb a large amount of punishment not just over the course of a full season, but individually through each game, too. Though the Pittsburgh offensive line has toughened up lately, it was largely terrible throughout the beginning of Roethlisberger's career.
Not to mention the fact that it's only a Grade 1 sprain. If it were higher than that, Roethlisberger could be expected to miss multiple weeks, but a Grade 1 is the lowest sprain, which means the time between games should be sufficient to play. Sure, he might not practice, but Ben will play even if he doesn't get practice reps. He probably doesn't need them at this point.
It's not a done deal, though it sure would be nice if Roethlisberger joined linebacker James Harrison on the inactive list on Monday. The 49ers really could use the break after dropping Sunday's game against the Arizona Cardinals.