As he explained to CSNWashington.com, Alzner listened to the message left by St. Louis Blues GM Doug Armstrong.
"I thought I got traded," Alzner told Comcast SportsNet. "I didn't really know what was going on at first. I was kind of wondering, 'Why is he calling me?'
"I was thinking, 'Can we be making trades right now? How can we just re-sign [a four-year extension with the Capitals] and then get traded? There was a whirlwind of thoughts going through my head, all in a matter of seconds. It was pretty funny."
Armstrong, of course, is part of Team Canada's management team for the Sochi Olympics, and was calling to notify the 24-year-old that he had been invited to the Canadian Olympic orientation camp next month.
"For me, this is big time," said Alzner. "It was a really, really cool feeling and I'm extremely happy.
"I have my work cut out for me if I want to be one of the better shut-down guys on that (team), but I'm definitely willing to try."
Alzner is one of 17 NHL defenseman invited to Canada's camp, which takes place from Aug. 25-28 in Calgary.