Rust (lower body) didn't practice Monday and is still being evaluated, per Michelle Crechiolo of the Penguins' official site.
Rust sustained the injury in Saturday's 4-3 loss to Vancouver. He has three goals, one assist, 24 shots on net, six blocked shots and eight hits through eight outings this season. If Rust sits out Tuesday's matchup against Minnesota, Evgeni Malkin could play on the same line as Sidney Crosby.