FILE - In this Tuesday, Aug. 18, 2020, file photo, Indianapolis Colts quarterback Philip Rivers (17) throws during NFL football training camp in Indianapolis. The Colts are one of three teams bringing back players who participated in more than 80% of snaps last season. A key newcomer for the Colts is Rivers. (AP Photo/Michael Conroy, File)

San Francisco 49ers defensive coordinator Robert Saleh, right, trains during NFL football training camp practice Saturday, Aug. 15, 2020, at the SAP Performance Facility in Santa Clara, Calif. (Xavier Mascarenas/The Sacramento Bee via AP, Pool)

FILE - In this Tuesday, Aug. 18, 2020, file photo, San Francisco 49ers head coach Kyle Shanahan watches during NFL football training camp in Santa Clara, Calif. The 49ers are one of three teams bringing back players who participated in more than 80% of snaps last season with Buffalo and Indianapolis just behind. (AP Photo/Jeff Chiu, Pool, File)

FILE - In this Sunday, Aug. 16, 2020, file photo, Carolina Panthers quarterback Teddy Bridgewater (5) throws a pass during NFL football training camp in Charlotte, N.C. With stalwarts like Cam Newton, Greg Olsen, Luke Kuechly and Trai Turner all leaving Carolina, the Panthers are the only team with less than half of snaps last season returning, At least new quarterback Teddy Bridgewater has some familiarity with offensive coordinator Joe Brady’s system, having spent the 2018 season together in New Orleans. (AP Photo/Nell Redmond, File)

FILE - In this Tuesday, Aug. 18, 2020, file photo, Carolina Panthers head coach Matt Rhule, left, talks with center Matt Paradis during NFL football camp in Charlotte, N.C. With stalwarts like Cam Newton, Greg Olsen, Luke Kuechly and Trai Turner all leaving Carolina, the Panthers are the only team with less than half of snaps last season returning, (AP Photo/Chris Carlson, File)

FILE - In this Monday, Aug. 17, 2020, file photo, Buffalo Bills wide receiver Stefon Diggs (14) catches a pass during NFL football training camp in Orchard Park, N.Y. The Bills are one of three teams bringing back players who participated in more than 80% of snaps last season. A key newcomer for them is Diggs, a big-play wide receiver. (James P. McCoy/The Buffalo News via AP, Pool, FIle)