Green Bay Packers linebacker Oren Burks is believed to have suffered a torn pectoral, NFL Network reported.
Burks will seek a second opinion on Monday to see if he can play through it or it will be season-ending.
As a rookie in 2018, Burks played in 14 games with four starts and 24 tackles.
Los Angeles Chargers coach Anthony Lynn also told reporters Saturday that tight end Andrew Vollert tore his ACL and is out for the season.
Jettisoned: Arizona Cardinals defensive lineman Darius Philon was released by the team Saturday after he was arrested on Friday in Phoenix on a charge of aggravated assault with a deadly weapon, according to documents obtained by NFL.com via the Phoenix Police Department.
Details of the arrest were not immediately available.
The Cardinals signed Philon to a two-year, $10 million contract in March. The 25-year-old Philon was a projected starter after signing in the offseason as a free agent. He started in Thursday night's preseason game against the Los Angeles Chargers. He had one combined tackle.
The former sixth-round draft pick out of Arkansas spent his first five NFL seasons with the Chargers, starting 19 of 54 career games with 9 1/2 career sacks.
Jags not ready: The Jacksonville Jaguars don't expect left tackle Cam Robinson and receiver Marqise Lee to be ready for the season opener.
Coach Doug Marrone provided an update on the two starters Saturday, saying "we just can't get them over the hump."
"We've got to go and start preparing to play without them, unfortunately," Marrone added. "It could change, obviously, but it'd be tough."
Robinson, a second-round draft pick in 2017, tore the anterior cruciate ligament in his left knee last September — during a Week 2 win against New England. Lee, who led the team in receptions in 2017, tore several ligaments in his left knee when Atlanta cornerback Damontae Kazee delivered a helmet-first hit to his knee in a preseason game last August.
Neither has practiced in training camp, and both remain on the PUP list.
Lions sign QB: The Detroit Lions announced they signed veteran quarterback Josh Johnson and free agent running back Justin Stockton.
The move comes after backup Tom Savage suffered a head injury in Thursday's preseason game against New England. Johnson would adds depth behind starter Matthew Stafford and David Fales.
A fifth-round pick by the Tampa Bay Buccaneers in the 2008 draft, Johnson has played for 12 other teams.
The Lions also placed wide receiver Jermaine Kearse on injured reserve and activated defensive end Trey Flowers (shoulder), who signed a five-year, $90 million contract in March, off the physically unable to perform list.
Pro Bowler back: Four-time Pro Bowl defensive lineman Jurrell Casey has passed his physical after starting the Tennessee Titans' training camp on the physically unable to perform list.
Tennessee also placed rookie linebacker D'Andre Walker, a fifth-round draft pick out of Georgia, on injured reserve.