Buffalo Sabres forward Casey Mittelstadt (37) celebrates his goal against the Boston Bruins with forward Tage Thompson (72) during the second period of an NHL hockey game Friday, April 23, 2021, in Buffalo, N.Y. (AP Photo/Jeffrey T. Barnes)

Buffalo Sabres goalie Ukko-Pekka Luukkonen makes a save during the first period of the team's NHL hockey game against the Boston Bruins, Friday, April 23, 2021, in Buffalo, N.Y. (AP Photo/Jeffrey T. Barnes)

Buffalo Sabres forward Sam Reinhart (23) is congratulated for his goal during the first period of an NHL hockey game against the Boston Bruins, Friday, April 23, 2021, in Buffalo, N.Y. (AP Photo/Jeffrey T. Barnes)

Buffalo Sabres defenseman Rasmus Dahlin (26) and Boston Bruins forward Brad Marchand (63) work for position during the second period of an NHL hockey game Friday, April 23, 2021, in Buffalo, N.Y. (AP Photo/Jeffrey T. Barnes)

Boston Bruins goalie Jeremy Swayman (1) and forward Brad Marchand (63) celebrate a victory over the Buffalo Sabres following the third period of an NHL hockey game, Thursday, April 22, 2021, in Buffalo, N.Y. (AP Photo/Jeffrey T. Barnes)