SAN JOSE, Calif. -- The Chicago Blackhawks will be down two regular defensemen when they take on the San Jose Sharks Friday night.

Both Nikals Hjalmarsson and Steve Montador were sent back to Chicago with upper body injuries while Montador was also placed on injured reserve earlier in the day.

Hjalmarsson missed practice on Wednesday and Thursday with what was believed to be the flu but coach Joel Quenneville changed that prognosis to an upper body injury fueling speculation of the possibility of a concussion.

“Things changed,” Quenneville said. “He’s day to day.”

The Hawks recalled Dylan Olsen from Rockford of the AHL Friday morning. He was en route to San Jose, missing the team’s morning skate. He and Sami Lepsito will both be in the lineup replacing Montador and Hjalmarsson.

“When he played here prior, I thought he was real solid for us,” Quenneville said of Olsen. “It gives us some size and some good presence. He did some good things for us.”

Lepisto has been a healthy scratch for the past 15 games while only dressing for 11 all season.

“When you have eight defensemen sometimes you have to make some tough decisions,” Quenneville said. “You have to commend him for sticking with it and being a good teammate. I was telling Sami the other day, ‘Be patient. Things can change quickly and here he is.’”

Corey Crawford starts in goal for Chicago while Antti Niemi has the net for the Sharks. The Hawks have lost a season high six straight games while San Jose has lost its last two.