The two-time Pro Bowler was initially hurt in the closing minutes of the Sept. 9 opener against San Francisco. He sat out the next week's game against Chicago, and returned to play at Seattle on Sept. 24. But he aggravated the injury against New Orleans, and came out of the Sept. 30 game in the second quarter after a 9-yard touchdown catch, his first of the season.
Jennings had hoped the injury would heal with treatment and strength work.
He traveled Wednesday to Philadelphia to see Dr. William Meyers, who specializes in abdominal and groin injuries.
St. Louis wide receiver Danny Amendola is recovering faster than expected from a right shoulder injury, and thinks there's an "outside chance" he can play against the Patriots in London on Sunday.
The Rams' leading receiver this season hurt his shoulder against Arizona on Oct. 4.
* Washington linebacker London Fletcher was being evaluated by a neurologist for a possible head injury and missed practice for a second consecutive day, putting his 15-year consecutive-games streak in doubt.
Coach Mike Shanahan said Fletcher was checked for about six hours by a doctor for a "balance issue." Shanahan listed the 37-year-old Fletcher as not practicing because of head and hamstring problems.
In other news, Redskins wide receiver Pierre Garcon said he has a tear in the plantar plate of his right foot and is hoping to avoid surgery to repair it, but won't know for a couple of weeks whether extended rest will allow the injury to heal on its own.
People with knowledge of the situation say that Garcon will remain sidelined at least until after Washington's Week 10 bye.
* The NFL fined Chicago receiver Earl Bennett $10,500 for wearing orange cleats in Monday night's win over the Detroit Lions at Soldier Field, Bennett confirmed to ESPNChicago.com.
Brandon Marshall also wore orange cleats, but it's not certain if he was fined.
Bennett told the website that he plans to appeal the fine because he wore pink shoelaces as part of the NFL's effort to raise awareness about breast cancer.
Bennett was fined twice last season for a total of $15,000 for wearing the cleats.
* The Cleveland Browns officially belong to Jimmy Haslam.
His $1.05 billion purchase of the NFL franchise from Randy Lerner was closed, just 9 days after the sale was approved by the league's owners.
New Browns CEO Joe Banner did not begin his position as expected because he went to Boston to be with his ill father, a team spokesman said.
* Denver cornerback Tracy Porter missed practice to see a doctor about symptoms he continues to experience following a seizure he suffered in August.
Porter is hoping to get medical clearance to play Sunday night against the New Orleans Saints, his former team.
Porter, who had no history of seizures, wasn't allowed to fly to the Broncos' last game, at San Diego on Oct. 15, after he began experiencing light-headedness and a racing heart.