The announcement from the Czech Ice Hockey Association came on Sept. 3.
Krejci underwent surgery on his left hip back on April 25, with his recovery time expected to be five months.
"David and I had been talking throughout the process," said Bruins General Manager Don Sweeney. "The Czech Republic team was also in contact with him pretty regularly to get updates as to where his recovery was. David had a general timeline that the doctors wanted to follow, based on how his health was and how he was progressing."
The Bruins' alternate captain has been a key player on Czech national teams through the years, including the 2010 and 2014 Olympics, as well as World Championships and World Juniors.
"This was very difficult decision for him," said Sweeney. "David's a proud guy, he wanted to play. It's a high-profile tournament. He's a key member of that team. He would have been at the forefront of their group, so it was a very difficult decision."
"We were supportive in allowing him the latitude to see how he was feeling during the rehab process and up until the final point when he had to make his decision. We are appreciative of David's approach, of [him] saying, 'You know what, I need to be 100 percent for the upcoming season' and not jeopardizing where the surgery and rehab are at this point in time and it says a lot about him, in terms of his commitment to the organization."
Krejci was on the ice for the Bruins' first captain's practice on Aug. 29. He had returned to the ice the week prior to get in some light skating. He only stayed on the ice for about 15-20 minutes, as he was just beginning to increase his intensity on the ice.
After that day's practice, Krejci addressed local reporters.
"If I'm 100 percent, then obviously I'm going to play," Krejci had said. "You don't want to be sitting on the sideline when you're 100 percent and you know you could be there. This is a pretty big tournament and I would love to be a part of it.
"But at the same time, if I'm not 100 percent, then I don't want to feel bad - I just want to get to 100 percent and play my best hockey."
Ultimately, despite his best efforts, Krejci was not be ready for the tournament.
"He had full support of the medical staff said Sweeney. "They have all been down this road before in terms of his previous hip surgery and the overall process and he was not looking to accelerate and no one wanted to push the envelope where he was going to jeopardize his season and his long-term health as a player and a person. Again, very respectful with the overall process that David followed throughout as was in communication with everyone but ultimately he had to make a very difficult decision."
Senyshyn on the Mend
Zach Senyshyn hasn't had the greatest luck this offseason, first missing the Bruins' mid-July development camp due to mononucleosis, and then undergoing an appendectomy on Sept. 4.
As a result, Boston's 15th overall pick from 2015 will not participate in the Bruins' rookie camp, which opens on Sept. 15, in order to recover. His participation level for training camp is undetermined at this time. Main camp opens on Sept. 22, with physicals and off-ice testing.
"Yeah, it's been a bit of a rough summer for Zach, oviously missing development camp with mono and now having gone through an appendectomy," said Sweeney. "Timing is obviously not ideal, but again, not something that he can control anyway."
"Everything was very positive coming out of the appendectomy; he feels good now. We're going to give him a couple of weeks, so that means he'll miss rookie camp and then come in with the vets and we will evaluate his health to get a better idea as to where he is, and then the timeline will kind of be unfolding as a result of how he feels and what he's able to do from there."
Senyshyn tallied 45 goals and 20 assists for 65 points in 66 regular season games for the Sault Ste. Marie Greyhounds of the Ontario Hockey League in 2015-16. The 19-year-old Ottawa native added two goals and seven assists in 12 postseason games in 2015-16.
While it has been an up-and-down offseason, Senyshyn was able to be part of Canada's National Junior Team summer evaluation camp during the first week of August, which involved Team Canada games against the U.S., Sweden and Finland at USA Hockey Arena in Plymouth, Mich.
Long-term expectations for the first-round selections have not changed, but short-term expectations could be affected by the offseason situations that were beyond his control.
"He'll be behind a little bit to start camp as a result of the appendectomy but he was a part of the showcase in Plymouth playing for Team Canada so he has been been skating, working out and making strides in a lot of the areas that we've asked him to continue to work on," said Sweeney.
"It's just unfortunate. There's sort of a natural progression - generally you return to development camp, you kind of get your benchmarks where you were a year ago and where you're at now, and then rookie camp is the same thing - you're playing against your peers and it gets you acclimated to go into main camp with more confidence and familiarity."
"Hopefully Zach will rebound quickly and be back competing during camp. He is excited to show how much progress he has made with his game and we look forward to him returning to full health."