Clifford, who was eligible to play against Colorado on Saturday night, missed six games with an upper-body injury. He has played in 16 games this season, scoring once.
Lewis is sidelined with what's being called a lower-body injury. He saw 10 minutes 22 seconds of ice time in Thursday's overtime loss to the New Jersey Devils, the 23rd game he's played in this season.
Also out with injuries are defenseman Matt Greene, center Jeff Carter and goalie Jonathan Quick.