Ryan was dealt to the Mariners on Sunday in exchange for pitcher Maikel Cleto, a hard-throwing right-hander that the Cardinals feel has a big upside.
"Cleto has a power arm that at times has reached 100 [mph]," Cardinals general manager John Mozeliak said in announcing the deal. "He's someone that could project as a back of the bullpen talent with additional development and experience."
The bullpen might be in Cleto's future, but in the past he's been a starting pitcher, including this year with Class A Advanced High Desert. In 23 games -- including 21 starts -- during the 2010 season, he posted a 4-9 record and a 6.16 ERA. Cleto also pitched in the Arizona Fall League for Peoria, going 2-1 with a 7.91 ERA in six starts.
Cleto, 21, rang up 83 strikeouts with 44 walks in 102 1/3 innings for High Desert, and opponents batted .305 against him. The Mariners protected him from being taken in the 2010 Rule 5 Draft by placing him on their 40-man roster.
Cleto is on the Cardinals' 40-man roster and will be at the big league camp in Spring Training.
Ryan, 28, a defensive standout, was the Cardinals' incumbent shortstop, but his status dipped when St. Louis acquired infielder Ryan Theriot from the Los Angeles Dodgers to fill that role. Pitcher Blake Hawksworth was dealt for Theriot on Nov. 30.
Shopped at last week's Winter Meetings at Lake Buena Vista, Fla., Ryan drew interest from several teams, including Pittsburgh, Baltimore, San Diego and, most recently, Minnesota. But Seattle, looking for infield depth, jumped into the picture.
Cleto, 6-3 and 235 pounds, was obtained by the Mariners from the New York Mets as part of a three-team, 12-player deal on Dec. 11, 2008.
"We gave up a very nice arm to acquire [Ryan]," Mariners general manager Jack Zduriencik said, "but when you can fill a need with a premium-position guy who can play multiple positions, that's somebody you've got to get."
Ryan might play second base for the Mariners with Chone Figgins moving over to third base, or he could provide depth or competition at shortstop with oft-injured Jack Wilson.
Last season, Ryan's average slid to .223 from .292 in 2009. He believed that right wrist surgery shortly before Spring Training hampered his swing and he never did feel right in exhibition games.
"I took that into the season and it didn't work out so well," Ryan said. "I got myself a little lost, lost a little confidence. I couldn't find my '09 swing."
Ryan told Seattle reporters that he was eager to return to the Pacific Northwest, where he played college ball for Lewis & Clark State in Idaho.
"You can't get better summers than in the Northwest," he said. "Those summers in St. Louis will crush you at times. That's some kind of humidity and heat. It'll be familiar stomping grounds."
Ryan had spent his entire career in the Cardinals' organization after being selected in the seventh round of the 2003 First-Year Player Draft. In four years with St. Louis, he batted .259 in 415 games.
Cleto (pronounced CLAY-tow), from the Dominican Republic, was signed by the Mets in 2006. In four Minor League seasons, he has a 10-27 record in 69 games (56 starts) with a 5.17 ERA. He has not pitched above the Class A level.
The Cardinals project that he could develop into a closer or setup reliever.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.