Marchand, who is recovering from surgery on his elbow, groin and abdominal area, won't be available to work with the Bruins on Thursday, but he should be fine for Boston's season opener, per Steve Conroy of the Boston Herald on Wednesday.
Sundqvist (knee) will take part in practices during training camp, but he isn't expected to participate in any preseason games, Jeremy Rutherford of The Athletic reports Thursday.