The Boston Bruins will be without Jaroslav Halak on Monday after the goaltender returned a positive COVID-19 test, head coach Bruce Cassidy said.

Dan Vladar will make his fourth start of the season against the Philadelphia Flyers. The 23-year-old is 2-1 this season with a 2.03 goals-against average and a .929 save percentage. 

The Bruins were already without goaltender Tuukka Rask, who has been sidelined since March 25 with an upper-body injury. Cassidy said Rask will not play Monday or Tuesday, but could join the Bruins later in the week.

Jeremy Swayman, who made his AHL debut earlier this season, will serve as Vladar's backup on Monday.

Halak, 35, has a 9-5-3 record this season with a 2.44 GAA and a .910 save percentage with two shutouts.

Boston enters play Monday sitting fourth in the East Division with a four-point lead over the Flyers for the final spot in the division.