Dyson injured his shoulder Monday making a catch. An MRI taken Friday before the Royals and Minnesota Twins were postponed by rain revealed Dyson has a strained lat.
"That's what it shows," Royals manager Ned Yost said. "We'll shut him down from throwing."
The game will be made up as part of a doubleheader Saturday.
The Twins will start a pair of rookie right-handers in the twinbill, scheduled to begin at 3:10 p.m. Cole De Vries (3-5) will pitch the first game against fellow Friday starter Will Smith (4-6), Kansas City's rookie left-hander.
Liam Hendricks (0-7) is set to start in the nightcap against right-hander Luke Hochevar (7-12).
With major league clubs able to expand rosters from 25 to 40 on Saturday, Yost said there is no need to put Dyson on the disabled list. Yost said the club would "probably have to bring an outfielder up" with Dyson's injury.
Dyson's best tool is his speed. He has 25 stolen bases in 28 attempts and is tied for ninth in the American League with five triples.
"He'll still be a valuable piece for us late in the game to be able to pinch run, so we can use him in that capacity," Yost said. "The only thing it limits is his throwing."
Dyson, who has hit .375 in his past 14 games, is hitting .270 with a .333 on-base percentage in 87 games, starting 73 in center, and 246 at-bats.
Dyson said he injured the shoulder while making a catch Monday at Fenway Park at the wall.
"I didn't feel a thing, but I kind of felt a little tightness on Tuesday," Dyson said. "On Wednesday, I really felt it. Right now, it's just day to day. It depends on how I feel. I'm still available to run."
He said it hurts "a little bit" when he throws.
"It doesn't bother me swinging," Dyson said. "It's not major-major, just a little soreness in there."
Dyson said "the goal" is to be able to return to the starting lineup before the season ends.
"But if not, I'll be ready for 2013," Dyson said.
Three outfield candidates with Triple-A Omaha on the 40-man big league roster who could be called up are Jason Bourgeois, Derrick Robinson and David Lough. Bourgeois, who was acquired in a trade during spring training from the Houston Astros, was on Kansas City's opening-day roster and hit .333 in 19 games. He has played 211 games in the majors with the Chicago White Sox, Milwaukee Brewers and Astros. Robinson and Lough have no big league experience.
The Twins recalled OF Matt Carson, who was hitting .282 with 14 home runs and 53 RBIs in 115 games with Triple-A Rochester. .The Twins placed OF Denard Span (right sternoclavicular joint strain) on the 15-day disabled list. . Royals bullpen coach Steve Foster has been named the minor league pitching coordinator, replacing Rick Knapp. Royals senior pitching advisor Bill Fischer will serve as the bullpen coach for the Twins series. Then minor league pitching coaches Larry Carter and Doug Henry will split the bullpen coaching duties for the remainder of the season. ...The Royals' rain out was their first since 2010 at Kauffman Stadium and the 75th in 40 years.