WILMINGTON, Mass — There was a collective sigh of relief around the Boston Bruins’ practice facility Ristuccia Arena Friday morning. Thankfully the team found out that the upper body injury that captain Zdeno Chara suffered in their 4-3 preseason shootout win Thursday night was not as serious as not only the collective souls of Bruins nation feared but also admittedly head coach Claude Julien did as well.

“Day-to-day,” Julien said of Chara and the upper body injury he suffered early in the first period Thursday and that kept him out for the rest of the game.

“That’s good news, for me. I thought last night that it could’ve been worse. That’s all I know. I’m not the doctor, obviously.”

When asked if the 6’9″ 256-pound anchor of his blue line — that will already be missing fellow rear guard Dennis Seidenberg (back) for eight weeks — will be ready for the season opener October 8 against the Winnipeg Jets, Julien again answered “day-to-day” with a smile.

Linus Arnesson, Chris Breen, Chris Casto, Tommy Cross, Torey Krug, Kevan Miller, Zach Trotman, Ben Youds and Jakub Zboril were the defensemen on the ice at practice for the Bruins on Friday. With the increasing chance that even more on that rather inexperienced list could sneak into the opening night roster — if even just as healthy scratches — increasing with the injuries to Chara and Seidenberg, the question marks surrounding the Bruins defense corps increase as well. The healthy defensemen know what challenges lie ahead and they’re ready to step up.

“They are two valuable pieces, but we won’t sit here and dwell on it,” said Krug. “If we have to step up and play more minutes than [we’ll do] whatever the case may be. But they are definitely two very important pieces [to our team].”