"He's doing fine," Chargers coach Mike McCoy said. "All the tests right now look good. It's great for the organization to go out and get a win for Malcom. I'll leave it at that and update you as time goes on."
Floyd was taken to a hospital for observation, McCoy said. A CT scan on Floyd's neck was negative, a team source told ESPN.
Floyd suffered the injury while going over the middle for a pass from Philip Rivers on the Chargers' first play from scrimmage of the third quarter.
As he was taking the ball in, Floyd was hit from behind by Allen. Floyd struggled to control the ball as Ryans approached him at full speed and delivered a blow that left the receiver motionless on the ground.
Players surrounded Floyd in the all-too-familiar ritual of waiting for medical personnel to stabilize him. Floyd eventually was placed on a backboard and lifted onto a stretcher.
"Just praying that he was OK, that it wasn't too serious of an injury," Ryans said. "It's hard any time you hit a guy. You're not trying to cause injury on anyone.
"It was just an unfortunate bang-bang play that happened. I was just praying that everything goes well and that he's OK."
Floyd had five catches for 102 yards before the injury.
ESPN's Ed Werder and Sal Paolantonio, ESPN.com's Phil Sheridan and The Associated Press contributed to this report.