Neither Kelly nor coach Claude Julien nor any of the other Bruins would divulge what was said in the room.
But something snapped them out of their funk.
"Claude came in a little bit later, but I think we were all equally upset about that first period," said Daniel Paille, who scored at 13:48 of overtime to end it. "Definitely, Claude let us know and it was a way for us to wake up. And, also, players were keeping each other accountable, too, so it was good."
Whatever was said, the Blackhawks managed only 15 shots over the next two-plus periods to Boston's 24. For the game, the Bruins had 50 hits — 10 by Milan Lucic — to 34 for Chicago.
"They're in the Stanley Cup final for a reason," Blackhawks forward Patrick Kane said. "It's not like you're going to have the momentum or dominate for three periods. Obviously, we'd love that.
"We know momentum is huge in the playoffs. You want to keep it as long as you can."
But Blackhawks forward Dave Bolland said they relaxed after taking an early lead and dominating the first period. Another goal was disallowed when the referee lost sight of the puck and blew the whistle moments before it rolled under Rask and over the goal line.
"You always have to have your foot on the gas against this team," Bolland said. "They're a physical team. You see the guys they have. They're a big team and they play hard and they're going to hit, so you've got to be ready for that."
Chicago coach Joel Quenneville said he didn't think the team lost momentum by having an extra day off before Game 1 on Wednesday and Game 2 on Saturday.
"We had a great first period," he said. "We did everything we wanted except get to two (goals)."