"It's too early to tell," coach Rex Ryan said. "He was there for the walkthrough and all that, but he didn't practice."
Harris is the Jets' leading tackler and it would be a huge loss to the NFL's top-ranked defense if he can't play. He injured the ankle during the first half of the regular-season finale against Cincinnati on Sunday, and watched from the sideline in the second half. Harris wasn't in the locker room during media availability.
Ryan, who wouldn't specify whether it was a high ankle sprain, wasn't sure if Harris would practice Wednesday.
"I think we'll move slowly on it," Ryan said. "You know, he's a guy that this is a familiar opponent, so we'll probably give him as much time as he needs."
Meanwhile, Harris' replacement, Ryan Fowler, is recovering from a head injury and was limited in practice. He was on the field during the half-hour the media are allowed to watch, but was wearing a red no-contact jersey.
Kenwin Cummings would step in if either Harris or Fowler can't play against the Bengals, who ranked ninth in the league in rushing. Cummings was signed as an undrafted free agent out of Wingate in 2008, and has been inactive for the past seven games after being signed from the practice squad.
"They tell you to always be ready to step in at any time," said Cummings, who could make his NFL debut in the playoffs. "It couldn't get any sweeter than that. First game, playoffs? You couldn't ask for anything more."
Safety James Ihedigbo left practice briefly after experiencing a stinger that left some tingling down his left arm.
"He looked like he got shot, but he's all right," Ryan said.
Ihedigbo is one of the team's top special teamers and also plays a significant number of snaps on defense.
"It was a pinch in my nerve in the shoulder," he said. "It was more fear than anything because I wanted to move it and I couldn't. I'll be fine. No biggie."
Also, punter Steve Weatherford didn't practice while resting his sore right hamstring. He was injured in practice last Friday, but punted against the Bengals on Sunday.
"I think they're just being smart," Weatherford said. "There's just a little soreness right now. I'll be a full participant Wednesday and Thursday. We're just cutting down on the reps and resting it a little today. ... I'm 100 percent playing, for sure."
Running back Thomas Jones, who finished fourth in the league with a career-high 1,402 yards rushing, and fullback Tony Richardson were given the day off. Ryan has rested both for one practice day the past few weeks.
"That's not injury-related," Ryan said. "Just keeping them rolling."