And that wasn't all. The Royals also obtained another right-handed starting pitcher, Wade Davis, from the Rays. Going to Tampa Bay with Myers are pitchers Jake Odorizzi and Mike Montgomery and third baseman Patrick Leonard.
Along with Shields and Davis, Kansas City is to receive a player to be named or cash.
"It really wasn't too much of a surprise. Obviously, the initial shock of being traded," Shields said on Monday. "But I've been being talked about over the last year and a half, and I've been kind of prepping myself for this day. To be honest, I didn't know which teams were interested in me. You hear the rumors, but I'm excited to be a Royal. There's a lot of young talent."
Shields is expected to jump right into the leadership role in the Royals' rotation, which was seen as the team's weakest department last season.
"Well, yeah," Royals general manager Dayton Moore said. "He was one of the premier starting pitchers in all of Major League Baseball and someone that was highly sought after in trades this offseason and we're 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 so we feel very good about where we are with the previous deals that we made -- trading for Ervin Santana and signing Jeremy Guthrie."
In MLB.com's list of the Royals' Top Prospects, Myers was ranked first, Odorizzi third and Montgomery sixth.
"It's not easy to give up prospects but it's important that we start winning games," Moore said.
Prospects acquired by Rays
- Wil Myers, OF: Myers, ranked No. 3 on MLB's Top 100 Prospects list and No. 1 on the Royals' Top 20 at the time of the trade, was arguably the best hitting prospect in the Minor Leagues. He appears ready for his first big league shot. Initially drafted as a catcher, Myers moved to the outfield after one year behind the plate and he should fit the mold of a run-producing right fielder in the very near future.
- Jake Odorizzi, RHP: Odorizzi was No. 30 on MLB's Top 100 Prospects list and No. 3 on the Royals' Top 20. This is the second time Odorizzi has been traded; he originally was drafted by the Brewers before being shipped to Kansas City in the Zack Greinke deal. The 2012 Futures Game starter shows four pitches that have the chance to be average or better. He can get his fastball up to 95 mph, sitting in the 92-93 mph range with plenty of sink. His curve can be plus at times, he has an above-average slider and his changeup grades out as average.
- Mike Montgomery, LHP: Montgomery, the Royals' No. 6 prospect, has seen his star fade a bit of late. Once thought to be one of the top left-handed pitching prospects in the game, Montgomery has scuffled more often than not for the past two seasons. Command issues have largely been the culprit as he walked 4.1 per nine in 2011 and 3.8 in 2012, along with allowing 10.8 hits per nine this past season. As much as he's struggled, Montgomery's pure stuff gives the Rays plenty to work with.
- Patrick Leonard, 3B: A product of the Craig Biggio-coached St. Thomas High School program in Texas, Leonard got an above-slot deal to sign instead of heading to the University of Georgia. His pro debut in 2012 -- he signed too late in 2011 to play -- was a solid one, especially in terms of showing glimpses of his power potential. He tied for the Appalachian League lead in home runs while finishing eighth in slugging percentage. While he may never be a high average guy, it does look like he'll make consistent contact to reach that power in the future.
- Top 20 Prospects: Rays | Royals
- -- Jonathan Mayo
The Royals already are considered to have a solid starting lineup and a strong, deep bullpen, so this trade likely will place them among the title contenders in the American League Central.
"Let's make something very clear. Billy Butler, Alex Gordon, Salvador Perez and Alcides Escobar signed here long-term with the full expectation that we, as a baseball operations department, would do everything that we can to put the best team on the field every single night," Moore said. "That's what we've committed to our fans, that's what we've committed to our players, so when an opportunity comes along that you can acquire a pitcher like James Shields and Wade Davis, we have to do it."
Shields, who'll turn 31 on Dec. 20, had a 15-10 record this year and a 3.52 ERA in 33 starts with 223 strikeouts. He piled up 227 2/3 innings, a big plus for the Royals who needed to lessen the load on a hard-worked bullpen.
Moore indicated that Davis, 27, will resume a starting role after pitching exclusively in relief for the Rays this year. He had a 3-0 record with a 2.43 ERA in 54 games in 2012 after making a combined 64 starts for the Rays from 2009 to 2011.
"I was working out to be prepared for that when the World Series was going on," Davis said of becoming a starter. "It was something I was hoping to get the opportunity to do, and I'll be ready.
"I think I've learned how to put my foot on the gas pedal and ... just be able to go out from the start of the game. ... I came up with [Shields], and he was the leader of the staff when I first got called up. He's the type of guy that rubs off on other people. Regular season and postseason, it was, 'We're going to go out and win every game,' and it didn't matter the opposing pitcher. 'We're going to be the difference.' He's brought that mentality onto all of us, and we've all latched on to it."
The deal gives the KC rotation some size -- Shields is 6-foot-4, 215 pounds and Davis goes 6-foot-5, 225.
It also adds some salary to the Royals' payroll. Shields will make $10.25 million in 2013 and $12 million in 2014, after which he could become a free agent. Davis' 2013 salary is $2.8 million and that goes to $4.8 million in 2014.
Royals owner David Glass had said he was willing to boost the 2013 payroll past the $70 million level for the right players. This could take it about $10 million beyond that.
"The Glasses have allowed us to create a great environment in which people like to work and they've given us the resources to build a strong farm system and make the necessary moves at the Major League level to improve and to win," Moore said. "It's time for us as an organization to win at the Major League level and we have to use all our resources. Our farm system is certainly one of them."
Shields was one of the most popular players in Tampa Bay history. He owns a career 87-73 record and 3.89 ERA and is the Rays' all-time leader in wins, starts (217), innings pitched (1,454 2/3), strikeouts (1,250), complete games (19) and shutouts (eight).
He got word of the trade from Andrew Friedman, the Rays' executive vice-president of baseball operations.
"I think I felt like something was going to happen this offseason," Shields said. "I was kind of hoping it wouldn't. I really like the organization and the Tampa Bay area. But Andrew felt like it was my time to go and here I am, I'm going to start a new chapter in my life and move on and try to help the Kansas City Royals."
The seven-year veteran has made a club-record four Opening Day starts, and 2012 was his sixth consecutive season of at least 200 innings. In his final start for the Rays, on Oct. 2 against the Orioles, Shields collected a club-record 15 strikeouts in a complete-game two-hitter with no walks, but took a 1-0 loss.
In 2011, Shields made the AL All-Star team and finished third in the AL Cy Young Award race.
Davis went 12-10 with a 4.07 ERA in 2010 and was third in the AL Rookie of the Year voting. In 118 career outings, including 64 starts, his record is 28-22 with a 3.94 ERA. As a starter, he's 25-22 with a 4.22 ERA.
Myers, who turns 22 on Monday, pounded a total of 37 home runs with 109 RBIs and a .314 average this year combined in Triple-A and Double-A. He was named the Minor League Player of the Year by USA Today, Baseball America and Topps. He's ranked No. 3 in the nation in MLB.com's Top 100 Prospects.
With B.J. Upton leaving the Rays for a five-year, $75.25-million deal with the Braves, Myers could get a shot at filling the vacancy in center field.
Odorizzi, 22, was 15-5 with a 3.03 ERA in 26 games this year combined for Triple-A Omaha and Double-A Northwest Arkansas. Called up in September, he made two starts for Kansas City and was 0-1. He was expected to have a chance to make the KC rotation this year.
This was the second major trade in right-hander Odorizzi's career. He was part of the Dec. 19, 2010, deal that sent Zack Greinke to the Brewers and brought Odorizzi, Escobar, Lorenzo Cain and Jeremy Jeffress to KC. Jeffress recently was dealt to the Blue Jays.
"I was a little surprised by it, with the timing of the evening and all that, but I'm excited -- I'll have a lot of opportunities with Tampa Bay. It's a young team just like here in Kansas City," Odorizzi said. "So I'm going to take it as an opportunity and make the most out of it."
The Royals announced the trade about 10 p.m. CT on Sunday.
Montgomery, 23, made a bid to make the Royals' roster in Spring Training 2011 but followed that with two lackluster seasons in the Minor Leagues. This year he was demoted from Omaha to Northwest Arkansas and finished 5-12 with a 6.07 ERA in a combined 27 starts.
Leonard, 20, hit 14 home runs with 46 RBIs and a .251 average in 62 games this year for the Rookie Burlington club. He was the Royals' fifth-round choice in the 2011 Draft.
Depth in the Minor Leagues enabled the Royals to make the trade.
"If you're going to win consistently in the Major Leagues, you have to have a rotation that's going to give you innings and compete and give you a chance to win," Moore said. "That's what our goal is, to put together a very good rotation and we feel like we've been able to do that."
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.