Davis caught two passes during Monday night's preseason opener and returned a kickoff 32 yards. In the Family Night Scrimmage, he scored on a 71-yard catch-and-run connection with Tim Couch.
"We really feel bad for the young man because he was doing a good job," Sherman said.
Davis was returning a kickoff Wednesday when he bounced off one of his blockers and then smacked into a member of the coverage team, defensive lineman Kenny Peterson.
Davis had a cup of coffee with the Packers last season and was re-signed in February. The Packers shipped him to NFL Europe, where he led the league this spring in kickoff returns with a 30.1-yard average with the Rhein Fire.