Boeser, 21, has been dealing with a groin injury.
"He's gotten better, but he isn't over the hump yet," coach Travis Green said, adding that Boeser may rejoin the team on the trip.
Boeser had two goals and two assists in Vancouver's 7-6 overtime win over Colorado on Friday. He missed the 3-2 win over Detroit on Tuesday and won't skate in Boston on Thursday.
Boeser, who finished second in Calder Trophy voting last season, has four goals and seven assists in 13 games this season.