To fill the roster spot, Kansas City will select the contract of infielder Tony Abreu from Triple-A Omaha on Monday.
The Royals had been platooning Betancourt with Chris Getz at second base, and manager Ned Yost said that Betancourt wanted more playing time.
"Yuni wants to play more. We had liked the setup that we had with Getz. It was just the time to do it right now," Yost said. "If we're going to change our culture, we have to have 25 guys that are invested in what we're trying to do. We're going to bring Abreu up and give him a shot."
Yost said that Betancourt was unhappy with his playing time and, as a result, wasn't on board with the rest of the team's mission, something that Yost passionately spoke about in his postgame press conference.
"We have been living in a losing culture here for many years. We cannot get over the hump. And in order for us to get over the hump, we have to have 25 guys who are solely invested in one goal, and that's turning this organization around to become a champion. That's it," the skipper said.
It's not about, 'how much do I play?' It's not about, 'do I have a job?' This is about 25 guys with one goal: that we're going out to try to win this baseball game tonight, and you have that goal night in, night out. And if you've got anybody else that is not on page with that, we will never change our culture. It's about 25 guys who respect each other, 25 guys that have the same common goal. That's how we're going to turn this losing culture into a winning culture."
Betancourt started 14 of the team's first 22 games before sustaining a right ankle sprain that sent him to the disabled list on May 3. He missed 27 games before returning on June 1, and had started 37 of 56 games since.
"Yuni did a great job for us. But he was a guy that wanted more playing time, and he would get upset when he didn't," Yost said. "Getz was playing good, and there were just situations. We're trying to win the ballgame every day, and we're going to put the best team on the field every day. This is an opportunity now for Yuni to go find a place where he can play more."
The 30-year-old Betancourt seemed to put emphasis on his injury for lack of playing time.
"It really didn't get me by surprise because I know my numbers, they weren't the best. And I know that we had a lot of good players down there in the Minors, and those guys, they deserve to play here every day," Betancourt said through translator and teammate Brayan Pena.
"It has been a very tough year because I was playing pretty much every day and I got hurt. So I missed like a month. I know that that injury, it would cost me a little bit, but at the end of the day, that's nothing I can control."
Betancourt, who returned to the Royals in the offseason following a trade from Kansas City to Milwaukee before the 2011 season, has struggled at the plate this season. He hit just .228 in 57 games with seven home runs and 36 RBIs.
The Royals have now made two moves in as many days, as first-base coach Doug Sisson was dismissed on Saturday and replaced with Rusty Kuntz.
"For me, Yuni's been a great teammate," outfielder Jeff Francoeur said. "Obviously, that's up to the front office. You saw that stuff with [Sisson] and different moves and stuff. Obviously, things haven't gone that well this year, and when things don't go well, changes are made sometimes. They're not easy, they're tough. ... Yuni's a great player and I have no doubt he'll get picked up by another team and be a part of it."
Following Yost's comments, players were questioned about the team's chemistry.
"It's good," Francoeur said. "It's tough when you've got a bunch of young guys, a young team, it's tough when you start losing. Guys get frustrated, and it can become about yourself and not about the team. Ned had a little meeting with us, and the players, we kind of talked amongst ourselves and said, 'There's no room for that. We've got two months left, 60 games to play hard, to be a team and have all the guys pulling for each other.'"
Getz now becomes the Royals' everyday second baseman. It also clears a spot for Abreu, who has spent the entire season at Omaha. In 103 games with the Storm Chasers, he hit .322 with nine home runs and 73 RBIs.
Abreu has big league experience, appearing in 65 games for the Dodgers in 2007 and 2009 and 81 games with the Diamondbacks in 2010. He's a career .251 hitter in the Majors.
Still at Omaha is second baseman Johnny Giavotella, who was recently named the club's Minor League Player of the Month for July after hitting .368.
The Royals have 10 days to trade, release or assign Betancourt to the Minors if he clears waivers.
"We've been scuffling for awhile, and when you're losing, people are accountable," Getz said. "They need to be accountable. Whether you're a coach, manager, player, whoever, you've got to win games and if you don't, they make moves. Sometimes it's worth it, sometimes it isn't, sometimes they just need to shuffle some things up. And I think that's the case."
Vinnie Duber is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.