The reunion between friends occurred a whole five days after the business side of the game that brought them together tore them apart, during batting practice on the field both called home for the entirety of their baseball careers, save the past week.

Joe Kelly and Shelby Miller, who in 2009 sparked a friendship so strong they stood as groomsmen in each other’s weddings, will face each other for the first time tonight as Kelly makes his Red Sox debut.

But before that there needed to be words exchanged. Hugs had to be given.

A wager needed to be made.

“He said if he gets a hit off me, I owe him $100,” Miller said. “I’m going to invite him over (Tuesday), keep him up, see how long we can play video games until the morning. See how long he can last.”

And Ben Franklins aside, the real competition will be decided by how each pitcher fares against the other eight players in the lineup. Miller will be making his third start since rejoining the rotation in late July and is coming off a win against San Diego his last time out. Kelly was hit hard during his last two starts, one a loss to those Padres a day before being sent to Boston with Allen Craig for John Lackey and a minor-league pitcher.

Both are used to competing against each other, but not on the baseball field. Video game screens are more their domain.

“We’re all competitors here,” Miller said. “If you don’t like to compete you probably wouldn’t be playing baseball. That’s just what it is. Obviously me and Joe compete at a lot of things and tomorrow will be another game. The biggest thing is going out there and trying to pitch your best and get a win for the team. I know we’ll both try to do that.”

Kelly, 26, and Miller, 23, met at Class A Quad Cities and became consistent roommates at subsequent minor-league levels as their careers took mirroring trajectories. The 2010 season at Quad Cities. 2011 split between Palm Beach and Springfield. 2012 stints in Memphis, 12 games for Kelly and 27 for Miller, before making their major-league debuts in the same year.

“We’re best friends,” Kelly said. “When you have a best friend you talk to them and help them out with anything. It goes both ways. I will just say that he’s like a brother to me. We’ve been together for a while.”

Kelly will jettison that sentimentality when he steps on the mound tonight.

“I’m trying to keep emotions out of it,” he said. “I’m trying not to get too amped or be too nonchalant. Just a happy medium.”

Kelly did some reconnaissance after the trade, watching a game at Fenway as a fan before being activated to the roster.

“Not one person knew I was there,” Kelly said. “I just wanted to catch a game and see how it was. I enjoyed it. Had a Nantucket local beer and heard people talk some smack.”

Manager Mike Matheny called the pending matchup a “distraction” but asserted that he believes both pitchers have the focus not to allow it to affect them.

“A lot is being made about it,” Matheny said. “(Miller) has been at this long enough to know that he’s a pro, he’s got to be. There are going to be some extra distractions out there if you allow them. Right now, we have to win every game regardless of who is pitching against us.”

And of Kelly, Matheny said: “We know he’s going to be ready to compete. He’s going to have his best game, as he has always done. He’s an athlete and a competitor. In big situations he always pitches well. He’s going to come out and show what he can do.”

That includes at the plate, where the fate of Tuesday’s pregame bet will be decided.

Kelly was asked what was more important: getting his old buddy Miller out or getting a hit off of him?

“Obviously you want to get everyone out,” Kelly said after a pause. “But I’d like to get a hit.”

Joe Trezza is a sports intern at the St. Louis Post-Dispatch. Follow him on Twitter at JoeTrezz" @JoeTrezz