Sanderson (lower body) has been ruled out for Monday's game against the Devils, Bruce Garrioch of Postmedia reports.
Sanderson exited the Senators' Opening Night matchup against Toronto due to a lower-body injury, and he'll be sidelined for a fifth consecutive game during the first half of a back-to-back set Monday. It's not yet clear when he'll be able to return, but his next opportunity to do so will be Tuesday against the Blues.