"We will see what coach [Mike] Tomlin says and we'll go with it," Arians said after Roethlisberger missed the most important practice – Thursday – of this short work week.
The Steelers will go through a walk-through Friday and play the 2-12 St. Louis Rams on Saturday. Arians said missing practice will not be a factor in the staff's decision on Roethlisberger.
"It's the same defense we've seen a number of times this year with a similar game plan," Arians said. "It's just a matter of getting him as healthy as he possibly can, so he can have some mobility."
Arians said that center Maurkice Pouncey, who has the same Grade 1 left ankle sprain as Roethlisberger, is in the same situation and will be a game-time decision as well.
Wide receiver Emmanuel Sanders (foot), though, is less experienced and would need to practice, so it appears he'll be ruled out of his third consecutive game.
The Rams are in a similar position with their quarterback, but have all but ruled Sam Bradford out with his sprained ankle.
Bradford's been listed as doubtful for the game and would be replaced by Kellen Clemens. When Rams coach Steve Spagnuolo was asked if there was any chance Bradford would play, Spagnuolo said, "He might come in and grab me by the throat and threaten to play, but I don't think he'll do that."
It will be the second consecutive game Bradford will miss because of his ankle sprain. Arians was asked why the Steelers are handling Roethlisberger differently.
"They are not in the same boat we are in," Arians said. "We are still playing for a bye and a lot of things, back-to-back 12-4 seasons. I don't know how many times that has happened but that's a goal right now, to win the next game and the last game, and then see where the chips fall."
Arians would not hazard a guess as to whether Roethlisberger is healthier at this point of the week than he was last week, but Arians said he was thankful for one variant – that this game's at home.
"It's huge for all the guys that have injuries," Arians said. "When you get on that plane, you swell like crazy. You work all night to get the swelling out. It's hard on them. ... That's one of the reasons why we left Maurkice at home, so he wouldn't get a setback just by flying."
(Read the full transcripts of interviews with Bruce Arians and Dick LeBeau here on our message board.)