Chargers coach Mike McCoy updated Floyd's status on Monday, claiming that the receiver will undergo further testing this week.
"It's unlikely he'll play this week," McCoy said. "They're going to continue to do some tests on him throughout the week just to make sure we're doing everything the right way."
Floyd will be wearing a cervical collar for at least a week and the Chargers have sent his scans to Dr. Robert Watkins, a back and spine specialist, for further evaluation. At this time, there is no plan for Watkins to examine the wide receiver.
Even though this is the second time in the span of a few weeks that Floyd has left the field on a stretcher -- he suffered a knee injury in training camp -- sources close to the receiver told ESPN NFL Insider Ed Werder that they don't believe he would consider retirement.
The Chargers said Floyd was "doing fine" on Sunday night and that he joined his teammates on the flight to San Diego following a 33-30 victory over the Philadelphia Eagles.
"It was great to have Malcom come back with us on the team plane last night," McCoy said.
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. 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.
"You talk about the type of guy he is, the first thing when you talk to him, he says, 'Gosh, I should have caught the ball,'" McCoy said. "That's Malcom for you.
"So he's in good spirits and he's working on getting his way back as soon as he can."
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, Adam Schefter and Sal Paolantonio, ESPN.com's Phil Sheridan and The Associated Press contributed to this report.