Jones practiced this week and had been listed as questionable. But the Giants liked what they saw and Jones passed a final test Saturday.
The Giants (5-7) have been "optimistic" about the prospects of Jones' return. He had been trending in the right direction and was listed as a full participant in practice Friday for the first time since the injury.
Coach Joe Judge was hoping to have a good indication of who his starter would be against the Cardinals by Friday night. He seemed to be leaning in Jones' favor.
"Look, I'm fairly optimistic," Judge said before Friday's practice. "At the same time, there is a ways to go and we have to be fair to him. I'm going to talk with the trainers and medical team and coaches to make sure we're all on the same page and do the right thing by this guy."
The first-place Giants (5-7) made plans with and without Jones, just in case. They are looking for their fifth straight win.
Jones started the first 11 games of the season before injuring the hamstring two weeks ago against the Cincinnati Bengals. He has completed 63.2% of his passes for 2,335 yards with eight touchdowns and nine interceptions.
Colt McCoy, who started last week with Jones out, went 13-of-22 passing for 105 yards with a touchdown and an interception against the Seahawks. He did enough for the Giants to win, but the offense doesn't have the same big-play ability with him at the helm. McCoy attempted one pass longer than 20 yards; it was his final one, intended for Sterling Shepard, but it came up short. He also didn't provide much by way of his legs, finishing with two rushing attempts for 2 yards.
Jones is second on the Giants with 403 rushing yards on 55 carries (7.3 YPC). But it's unlikely he will be the same rushing threat he was before hurting his hamstring.