Royals general manager Dayton Moore is going all-in for 2013.

On Sunday night, the Royals pulled off arguably the biggest deal of Moore’s six-year tenure, acquiring veteran right-handers James Shields and Wade Davis from Tampa Bay in a six-player deal that sent prized outfield prospect Wil Myers, the consensus minor-league player of the year, to the Rays.

The deal also sends Royals pitching prospects Jake Odorizzi and Mike Montgomery and minor-league third baseman Patrick Leonard to Tampa. The Royals will also get a player to be named later or cash.

“No, it’s not easy to give up prospects,” Moore said. “But it’s important that we start winning games.”

The Royals, who finished 72-90 last season and haven’t made the playoffs since winning the World Series in 1985, have had just one winning season since the start of 1995. They’ve lost 90 or more games in eight of the last 10 seasons.

“Let’s make something very clear,” Moore said, “Billy Butler, Alex Gordon, Salvador Perez and Alcides Escobar are signed here long-term with the full expectations that we as a baseball operations department would do everything we can to put the best team on the field every single night.

“That’s what we have committed to our fans and that’s what we’ve committed to our players, so when an opportunity comes along, when you can acquire a pitcher like James Shields and Wade Davis, we have to do it, because that’s what we’ve committed to our team, we’ve committed to our organization. It’s time to start winning games.”

Some of the Royals’ current players greeted the news with joy.

“IM DOIN ONE ARMED CARTWHEELS THRU THE PLAZA,” tweeted pitcher Danny Duffy, who is recovering from Tommy John surgery.

Everett Teaford, another Royals pitcher, tweeted, “This is a game-changer for the #Royals. Sad to see Jake, Monty and Wil leave but excited for our future!”

In Shields, the Royals are getting a much-desired front man for their rotation. He was 15-10 last season with a 3.52 ERA in 33 starts and has an 87-73 career record with a 3.89 ERA in 218 games.

Shields turns 31 on Dec. 20 and is under club control for two years. He will receive $10.5 million in 2013, and the Royals will hold a $12 million option with a $1 million buyout for 2014.

“He’s one of the premier starting pitchers in all of major league baseball and somebody who was highly sought after in trades this offseason,” Moore said. “We were fortunate to have the prospect package that would allow us to consummate a deal of this caliber. Getting James Shields and Wade Davis upgrades our rotation immediately.”

Shields told the Tampa Bay Times, "I thought I might be able to squeeze in one more year, but that was kind of being selfish. I'm excited to go over there, but this is definitely a sad day for me and my family. I've been here 12 years. We made this our second home, and we're definitely going to miss it. I have a lot of good memories here, and the fans treated me as good as possible."

Davis, 27, made 64 starts for the Rays from 2009-11 before pitching exclusively last season as a reliever. He was 3-0 last season with a 2.43 ERA in 701/3 innings.

Myers turns 22 today. He batted a combined .314 last season in 134 games at Class AAA Omaha and Class AA Northwest Arkansas with 37 homers and 109 RBIs.

Odorizzi, 22, was generally viewed as the Royals’ most advanced pitching prospect after going 15-5 with a 3.03 ERA in 26 games for Northwest Arkansas and Omaha. He was 0-1 in two big-league starts after a September call-up.

Montgomery, 23, was once viewed as a potential No. 1 starter before regressing over the last two seasons. He was 5-12 with a 6.07 ERA last season in 27 starts at Omaha and Northwest Arkansas.

Leonard, 20, was the club’s fifth-round pick in the 2011 draft and made his pro debut last season, batting .251 with 14 homers and 46 RBIs in 62 games at short-season Burlington.

For the Royals, though, this deal was all about overhauling a woeful starting rotation. The first pieces were set in place when they acquired right-hander Ervin Santana from the Los Angeles Angels and retained free-agent right-hander Jeremy Guthrie.

But the Royals felt they still needed a No. 1 starter — or something very close — and Myers’ name buzzed around last week’s winter meetings as a potential trade piece. Drafted in the third round in 2009 and signed for $3 million, Myers was a poster child for the Royals’ draft strategy: paying for first-round talent in the later rounds.

Myers thrived in the minor leagues and was named Baseball America’s player of the year, following the Angels’ Mike Trout, Rays’ Jeremy Hellickson and Braves’ Jason Heyward.

But Moore didn’t hesitate to make the trade, which gives the Royals four new starting pitchers since their July 20 trade for Guthrie.

“If you’re going to win consistently in the major leagues,” Moore said, “you have to have a rotation that gives you innings, competes, gives you a chance to win — and that’s what our goal is: to put together a very good rotation, and we feel like we’ve been able to do that.”