SAN JOSE, Calif. -- Strong safety Kurt Coleman became the league-leading seventh member of the Carolina Panthers to go into the concussion protocol this season, but that’s not close to any kind of record.

The Cleveland Browns had a reported 14 concussions last season and the San Diego Chargers 13.

According to ESPN Stats & Information, that’s the most of any team over the last three seasons when concussions came to the forefront in the news.

Carolina coach Ron Rivera doesn’t understand why his team has had so many concussions this season after having five all of last year.

“I’m not sure if it all goes back to the way things are in terms of preparation of a season, starting with how limited OTA, mini-camps and then the hitting in training camp," Rivera said on Wednesday as the Panthers began preparing for Seattle at San Jose State University.

“Who knows? I really don’t, and it would be unfair of me to say so."

The Panthers (4-7) have had nine players go into the protocol since training camp. Defensive end Kony Ealy was in the protocol early in camp and wide receiver LaRon Byrd was placed on injured reserve with a concussion in August.

During the season, left tackle Michael Oher, quarterback Cam Newton, middle linebacker Luke Kuechly, cornerback Daryl Worley, linebacker A.J. Klein, safety Colin Jones and now Coleman have been in the protocol.

Oher was placed on injured reserve last week after missing seven straight games with a concussion. Kuechly missed Sunday’s start at Oakland and he didn’t practice on Wednesday, making him doubtful for Sunday’s game at Seattle.

Coleman will be replaced by veteran Michael Griffin on Sunday with Cole as his backup.