Wagner had to waive his no-trade clause before the deal with the Mets could become official. Major League Baseball gave the Red Sox a window on Tuesday to speak with Wagner directly, at which point it was relayed to the power lefty that Papelbon was in favor of him coming to Boston.
"He actually went out of his way to -- while we had our window to talk directly with Billy Wagner, [Papelbon] went out of his way to make sure Billy knew that he was more than welcome here," said Epstein. "I think the way Pap phrased it was that 'no one in this clubhouse wants him more than I do."'
Papelbon had expressed some reservations a couple of days ago about how such a move would impact the dynamic of Boston's bullpen, in which roles have been defined clearly for the past several weeks. However, Papelbon never said anything derogatory about Wagner as a pitcher or a person.
But as sometimes becomes the case in Boston, the story took on a life of its own, and Wagner even sent some barbs back toward Papelbon through the New York media.
Wagner will join the Red Sox on Thursday, and Papelbon looks forward to welcoming him to the team.
"I think the biggest thing is he's going to bring some competitiveness to the ballclub, not just to the ballclub, but to the bullpen," Papelbon said. "Hopefully, he will help us in that stretch run towards a championship. I know the only reason he's coming over here is to win a championship, and that's something everybody's on board with."
An elite closer throughout his career, Wagner is in the early stages of his comeback from reconstructive surgery on his left elbow. By next season, Wagner hopes to be closing somewhere again. But for the rest of 2009, he will be one of several Boston setup men in front of Papelbon.
"I've watched him throughout the years," said Papelbon. "The biggest thing is he pitches with heart. I love guys like that. I like guys who go out there and they wear their heart on their sleeve, and with that 'I'm going to get you or you're going to get me' type of attitude. I'm actually looking really forward to him coming here and kind of picking his brain, seeing how he works, and maybe picking up a couple things from him."
The Red Sox know that Papelbon is a candid speaker, and seemed to take even his initial public comments with a grain of salt.
"I think Pap feels like he was misunderstood. He's not a Rhodes Scholar to begin with, obviously," quipped Epstein. "When I talked to him directly about it, he couldn't have been more excited about the prospects of adding Billy Wagner."
Though the Red Sox have made it clear they won't put a heavy burden on Wagner, considering that he's less than a year removed from surgery, Papelbon is confident that the lefty can make an already strong bullpen even better.
"It's a great feeling," Papelbon said. "When you get down to the stretch run and the postseason, and when you get in the postseason, there's a lot of weight that gets put on that bullpen. That's the part of the season when you have leads in the later part of innings, and games, they need to be won. So that's big."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.