"Really, it was mostly about Mookie," said Cherington. "When a guy is performing at the level and doing it the way he's doing it and controlling the strike zone and performing in all different areas of the game, that kind of guy deserves consideration. We happen to have a need for as many good players as we can get, particularly guys that can move around positions, cover different spots. We talked about it for probably two or three days and just decided it was the right time."
The place happened to be Yankee Stadium, though Betts was not in the lineup for Saturday's game, but he will make his first Major League start on Sunday night.
"Last night, I was in my hotel room, me and my fiancé had just ordered pizza and were going to go into the hotel, then [Triple-A Pawtucket manager Kevin Boles] called me and told me to come back to the field, told me he had something to tell me," Betts said. "He didn't want to do it over the phone. Once I got there, he let me know, and the rest is history."
Betts, the team's No. 5 prospect, according to MLB.com's Prospect Watch, has rocketed through Boston's farm system after being taken in the fifth round out of high school in 2011.
"I think I'm as ready as I'm going to get," said Betts. "Only time will tell, getting out there and playing and learning more will tell if I was ready or not. But the front office felt I was ready; I have to feel like I'm ready as well."
To make room for Betts on the roster, the Red Sox optioned righty Rubby De La Rosa to Pawtucket.
Perhaps Betts would have made his first start Saturday if not for the fact that Masahiro Tanaka was starting for the Yankees.
"There was some thought into that," said Farrell. "That doesn't mean he won't play against right-handers. We have every intention of him being in the lineup tomorrow but, again, I thought just a day to come in and get his feet on the ground, go through a normal work day was the way to go here."
Betts will get plenty of chances to play, mainly in center and right.
The Red Sox also have Daniel Nava, Jackie Bradley Jr., Brock Holt and Jonny Gomes in the outfield, but Holt can also play several infield positions.
"The best way I would probably categorize it is there's five guys for four positions, which includes center and right and the left side of the infield," Farrell said. "Brock's versatility lends to being able to get close to everyday at-bats in these positions. What our goal is is to get a minimum of five days a week or six days a week for the younger players, and we feel like we can do that with this alignment."
Betts, 21, has split time this year between Double-A Portland and Pawtucket after being named the organization's Minor League Offensive Player of the Year in 2013. Over 77 total games this year, he hit .345 with eight homers, 70 runs, 48 RBIs and 29 stolen bases.
"You want to be sure," said Cherington. "You want to feel good that it's the right time and that you've sort of asked all the questions that you need to ask. But every question we asked, the answer was yes. In the minds of the Minor League staff, people around him, people here, it just seemed like the right thing to do. We're excited to see him here. He's a good young player."
Betts, who has started at both second base and in the outfield in the Minors this year, reached base in 66 consecutive regular-season games in a run that spanned from 2013-14 and included play at Class A Salem and Double-A Portland.
"Nobody can predict exactly what will happen, but we're confident that he'll come up here and just be himself and this will be a great experience for him," said Cherington. "He'll go through his transition like everyone else does. We're at a point where we're looking for as many good players as we can get. He's one of them, so he's here."