Jennings has missed three straight games with a left thumb injury, while Pierre-Paul sat out practice Wednesday with a groin problem.
"We're rocking this week," Jennings said Thursday after being a limited participant in practice.
He began taking real reps with the first-team offense this week after spending most of the previous three weeks on the side or with the scout team. Orleans Darkwa has started at running back for the Giants each of the past two weeks, with Bobby Rainey handling a substantial workload as the passing-down back.
The Giants have the 27th-ranked rushing attack, averaging 83.6 yards per game.
"[Jennings is] coming along. We're keeping our fingers crossed," offensive coordinator Mike Sullivan said. "I know he's been chomping at the bit and he's been really close last week and we were hoping he could've been there for us. Of course, it didn't work out and he wasn't able to play. Excited. He did more [Thursday]. It's a wait-and-see type situation. Keep our fingers crossed. We'd love to have him back."
Pierre-Paul was hurt in Sunday night's loss to the Green Bay Packers. He didn't seem to think his groin injury was anything serious.
"No question I'll be out there," he said Thursday.
Pierre-Paul would've been a substantial loss if he was unable to play. The Giants are last in the NFL with four sacks.
Defensive end Olivier Vernon (wrist) also remains on the injury report, although he was a full participant in practice. Vernon and Pierre-Paul each have one sack this season.
The Giants who didn't practice Thursday and are likely to miss Sunday's game are cornerback Eli Apple (groin), safeties Nat Berhe (concussion) and Darian Thompson (foot) and offensive tackle Marshall Newhouse (calf).
Wide receiver and returner Dwayne Harris (toe) also missed practice but could be ready for the Ravens.