Rams coach Steve Spagnuolo said the decision will be made just before the game between St. Louis (0-5) and the Cowboys (2-3).
Bradford has a high sprain in his left ankle and has been wearing a protective boot all week. He has not practiced on the field since he was injured last Sunday against Green Bay.
"Obviously he didn't come out here and practice so we didn't think he was healthy enough to do that," Spagnuolo said. "We'll take it one day at a time and we'll see where we're at on Sunday."
Spagnuolo said Bradford tried to do some work with a team trainer Friday morning.
"Sam, he's a competitor. He certainly wants to try to make this happen," he said. "There are a lot of segments to it that we have to figure out."
Feeley began his NFL career in 2001 but he has not started a game since 2007. He is 7-8 as a starter in the league.
From 2008 through 2010, Feeley did not attempt a pass. This year, when Bradford sustained a finger injury in the opener against Philadelphia, Feeley relieved him in the fourth quarter and attempted five passes. He completed one, for 21 yards.
In practice this week, Spagnuolo said Feeley has looked good.
"He's taken all the reps to this point and I think he's done a nice job," Spagnuolo said. "I thought we were pretty smooth out there today, which is supposed to happen on Friday."
Running back Steven Jackson said if Feeley gets the call, his teammates are there for him.
"He knows the offense. He knows the game plan," Jackson said. "He's going to need our help, all 10 (other) guys on the field, to help execute the play. But he's a veteran that we know if he gets in trouble, he knows how to get us out of trouble. And if we need to lean heavily on the run game, I'm prepared to do so as well."
Feeley has been preparing this week as a starter and said that's the only way he should be thinking.
"I think you have to. As a backup quarterback, that's the nature of the game where you have to go into the game, even when you're not getting reps, as you're going to be the guy because in the flash of a moment, one play, you can go in and play," Feeley said. "My mindset doesn't change. Maybe the sense of urgency does and the fact that I'm getting reps out here and the likelihood of me playing is probably a little stronger than it was."
He acknowledged he is getting acclimated with the offense under new coordinator Josh McDaniels that has so far scored an NFL-low 49 points. Since he doesn't work with it week in and week out, that's the way it is.
"That's kind of the misfortune of playing in the backup spot is that you don't get many reps with the 1s and you're primarily focused on running the service teams," Feeley said. "The key is as the backup, is when you're watching the first unit you have to take every mental rep as if you were in there. I've been around here a while and I've been around awhile so I'm pretty familiar with doing that."
A couple of his offensive linemen agree.
"We have to block for whoever's back there," left tackle Rodger Saffold said. "We still have to do a great job no matter what. We believe in A.J., too."
Center Jason Brown said Feeley has had a good week of practice.
"A.J.'s a vet and everyone knows that A.J. is qualified," Brown said. "He's smart and he's a leader. He's stepped in and everything has been seamless."
While emphasizing he won't make the decision on Bradford playing Sunday, McDaniels said if the second-year signal caller does play, not practicing all week should not be a problem.
"Obviously, Sam's in there seeing and hearing and learning everything we're doing," McDaniels said. "He knows what we're doing. We didn't reinvent the wheel this week, and he's a smart guy."
If it's Feeley, the Rams will be fine, McDaniels said.
"This is not his first rodeo in terms of an opportunity to come in and potentially play in a game like this," McDaniels said. "So he knows what we're doing."