CHARLOTTE, N.C. -- Jonathan Stewart will miss his third straight preseason game Thursday night at Baltimore and Panthers coach Ron Rivera isn't ruling out the possibility of putting the running back on the physically unable to perform (PUP) list.
If that happens, Stewart would miss at least the first six weeks of the season.
"At this point anything is an option," Rivera said following Tuesday's practice. "What you're hoping is you can get him on the football field and we'll see once the doctor gets a chance to look at him."
Stewart, who's battling back from surgery on both ankles, is continuing to work with trainers on the side but is keeping a close eye on the plays being run during practice.
He has yet to practice with the team.
Rivera said the sixth-year NFL running back will meet with team physicians soon -- though he isn't sure exactly when -- to determine if he's close to being ready to return to the practice field.
As for the Sept. 8 season opener against Seattle, Rivera doesn't know what to expect.
"You'd love to have him but we'll have to wait and see how it goes," Rivera said. "It's going to take a little time."
Stewart has turned down several interview requests to talk about his injury. He has battled ankle, foot and toe problems since entering the league as a first-round draft pick out of Oregon in 2008.
And while Stewart takes some good-natured ribbing from teammates for all of the practice time he's missed through the years -- he's sat out much more than he's practiced -- he was pretty reliable up until last season when it came to playing games.
He'd played in 71 of 73 games in his career prior to landing on injured reserve the final seven games of last season with what the team described as a high ankle sprain.
Stewart said at the start of training camp he had surgery on both ankles earlier this offseason but didn't give a timetable for his return.
The Panthers were counting on Stewart, Williams and Mike Tolbert to be a huge part of the offense this year with new offensive coordinator Mike Shula planning to return to a more traditional running game.
Panthers quarterback Cam Newton said Tuesday that he doesn't think Stewart will need a lot of reps to be ready.
"We all know what the situation is and we just hope that when he comes back, he comes back healthy," Newton said. "We don't want him to rush anything. We know what he brings to the table."
Stewart's best season came in 2009 when he ran for 1,133 yards and 10 touchdowns.
In the three seasons since Stewart has amassed 1,867 yards rushing and only seven touchdowns on the ground. Last year was his least productive as a rusher, gaining only 336 yards and averaging a career-low 3.6 yards per carry.
He was used more frequently as a receiver coming out of the backfield the last two years under former offensive coordinator Rob Chudzinski, catching 64 passes for 670 yards and two touchdowns.