Jovan Belcher showed signs of pervasive brain damage like that found in other deceased NFL players, according to a neuropathologist.

Belcher shot and killed his girlfriend in 2012 before committing suicide.

In a report obtained by "Outside the Lines," Dr. Piotr Kozlowski writes that he detected neurofibrillary tangles of tau protein, which is identified with chronic traumatic encephalopathy. The tangles were distributed throughout Belcher's hippocampus, an area of the brain involved with memory, learning and emotion.

Dozens of former NFL players have been diagnosed posthumously with CTE, a neurodegenerative disease linked to dementia, memory loss and depression. The disease, researchers say, is triggered by repeated head trauma.

Belcher's body was exhumed one year after his death, and his brain was examined two weeks later.

If it can be shown that Belcher did have CTE, Belcher's daughter and mother, together, would be eligible for up to $4 million under the proposed concussion settlement between the NFL and former players.

Morris Claiborne's season has ended because he tore a patellar tendon in his left knee.

Claiborne suffered the noncontact injury on a third-and-3 play with 5:52 left in the first quarter. He did not return to the game, and owner and general manager Jerry Jones said initial fears were a torn anterior cruciate ligament.

Claiborne walked out of the Dallas Cowboys' practice facility last week when informed that he'd lost his starting job to Orlando Scandrick.

Joe McKnight has suffered a ruptured Achilles during a Thursday practice.

McKnight had emerged as a pass-catcher for the Kansas City Chiefs, catching six passes for 64 yards and two touchdowns in Week 3.

Vernon Davis missed Week 3 with a deltoid ligament injury in his left ankle and will be a game-time decision for Week 4 against the Philadelphia Eagles.

Davis was initially told he would miss 2.5 weeks with the injury.

"It feels a lot better than last week," he said.

Davis has practiced in a limited fashion all week and was listed Friday as questionable.

Arian Foster will be a game-time decision and is questionable for Week 4 due to a hamstring injury.

Foster was a late scratch in Week 3 due to the injury.

Foster rushed 55 times for 241 yards in the first two weeks of the season. 

Calvin Johnson returned to practice for the Detroit Lions on Friday after missing two days with an ankle injury.

Johnson did a full complement of work during the team's individual workouts.

Johnson plans on playing against the New York Jets in Week 4.

"He's one of those guys that physically, he's an unusual individual," Lions coach Jim Caldwell said before practice Friday. "He responds quickly to treatment. He bounces back pretty quickly for the most part. What would ordinarily take some guys a little bit longer, he seems to be able to fight his way through it.

"He has an extremely high pain tolerance, as well, and he prepares and takes care of his body every single day of the year. That's where his focus is, and I think he benefits from that sort of regimen."

Matt Cassel has been played on injured reserve after sustaining "several fractured bones" in his foot in Week 3.

Teddy Bridgewater will assume duties as the Minnesota Vikings' starting quarterback.

Bridgewater completed 12 of his 20 passes for 150 yards after replacing Cassel against the New Orleans Saints.

Dennis Pitta underwent surgery on his dislocated right hip and is lost for the year. The procedure comes one day after the tight end suffered the non-contact injury in a Week 3 win over the Cleveland Browns.

It's the same right hip that Pitta fractured and dislocated last summer, an injury that cost him much of 2013.

The nature of the injury brings into question whether Pitta's playing career is now in jeopardy.

"I don't know the ramifications of that long term," Harbaugh said. "I'm going to be really hopeful for Dennis' return and I'm sure we'll learn about that in the coming weeks."

Danny Woodhead will miss the remainder of the season with a broken fibula.

Woodhead was an excellent fit at running back for the San Diego Chargers due to his versatility.

"We're going to miss him. But we've got to move on," Mike McCoy said.

Kyle Rudolph is expected to miss six weeks with sports hernia surgery.

Rudolph left the Minnesota Vikings' Week 3 loss to the New Orleans Saints with a groin injury.

The Vikings have targeted Rudolph 17 times this season.