NHL Commissioner Gary Bettman was also inducted Thursday but was unable to attend the game Wednesday.
After the game, Thomas was able to catch up with Bruins captain Zdeno Chara, goalie Tuukka Rask, forwards Brad Marchand, Patrice Bergeron and David Krejci and members of the training staff.
"It had been a long time," Thomas said. "I hadn't seen anybody from the team. … I had a blast seeing those guys."
Being inducted into the U.S. Hockey Hall of Fame has caused Thomas to reflect on his career that included winning the Vezina Trophy as the NHLs' top goalie in 2009 and 2011, winning the Stanley Cup with Boston in 2011, when he also won the Conn Smythe Trophy as MVP of the Stanley Cup Playoffs, and a silver medal with the U.S. at the 2010 Vancouver Olympics.
It's also led him to reveal the troubles he's had since retiring because of a concussion he sustained during his final NHL season while playing for the Panthers in 2013-14.
"At the beginning of December, there was a concussion that changed my life," Thomas said. "I woke up the next morning after it and I couldn't decide what I wanted to eat, where I wanted to go. I couldn't plan a schedule. I survived following the team schedule the rest of the year and just made it through that season."
Thomas said he was able to function on the ice that season -- he was traded to the Stars and finished the season with Dallas before representing the U.S. at the 2014 IIHF World Championships -- but had trouble coping away from the game.
"On the ice, I was able to be like 97 percent maybe, 95 percent of what I was before, but off the ice, like I said, I still can't choose," he said. "I'm so much better, but I wake up every day and basically I have to reorder everything in my mind for the first couple hours of the day and then make a list and try to make some choices to get some stuff done, on which I have gotten to the level that I can."
Thomas choked back tears while talking about his years away from hockey and how he was unable to even watch games on television.
"I didn't want to talk about this," he said. "I didn't want to talk. I didn't want to tell the world this stuff. Not till I felt ready, and I didn't feel ready yet. But here I am."
Not wanting to bother his former teammates while they were busy playing games, Thomas said he leaned heavily over the past few years on his wife, Melissa, his brother Jake, his mother and his children.
"That's what kept me going," he said.
After getting through the darkest moments when he didn't know how to value his career, which he finished with a 214-145-49 record, 2.52 goals-against average and .920 save percentage, Thomas said he has no regrets.
"I ended up learning so many lessons out of the experience," he said. "It brought me tighter with my family. It taught me a value for life and a value for my brain that I've never had before. And I have appreciation for everything that I never had before."
Being inducted into the U.S. Hockey Hall of Fame and preparing to make his acceptance speech Thursday added to that appreciation.
"Being welcomed back into the arms of the hockey family, so to speak, has been great," Thomas said. "It's reminded me of all the great people that I crossed paths with all throughout my career. It's been very impactful."
And participating in the ceremonial face-off Wednesday gave Thomas a brief opportunity to enjoy being on the ice again and remember what it was once like.
"That is an atmosphere that I had done quite a bit over my lifetime, but it had been a long time and I didn't know what it was going to be like," Thomas said. "It actually felt pretty comfortable and it was great. It was great."
