SURPRISE, Ariz. -- Camp began with a wealth of eight or nine pitchers who were considered possible starters. Good thing, because the piggybank has been tapped.

Left-hander Mark Redman and right-hander Zack Greinke, considered locks for the Royals rotation, are off the list.

Redman underwent arthroscopic surgery for torn cartilage in his left knee on Monday. He'll miss a month or more but a better estimate is expected next week when team physician Dr. Steve Joyce examines him.

Greinke has been gone for 10 days, leaving camp because of undisclosed personal matters. No one has ventured a guess on when or if he'll be back.

Now the rotation appears to include Scott Elarton, Runelvys Hernandez and Joe Mays with Jeremy Affeldt, Denny Bautista, Mike Wood and perhaps J.P. Howell competing to fill out the five spots in the rotation.

"Everybody just kind of moves up," manager Buddy Bell said. "We're closer to putting one together I can tell you that. We've got to come up with an Opening Day starter in the next couple of days."

Elarton is the leading candidate for that assignment.

Home run derby: Outfielder Chad Allen's left foot obviously feels better. Much better after he banged a two-run homer in his first Spring Training at-bat in Tuesday's 9-3 win over the Colorado Rockies.

The Royals had three homers in the eighth inning. Paul Phillips also hit a two-run shot and Esteban German unloaded a three-run blast.

"Guys were going against a fastball pitcher and were being aggressive and it came out like that," Allen said.

Allen hadn't played since banging a foul ball off his foot in an intrasquad game.

Bell thought all four of his pitchers did well even though Bautista gave up two runs on two hits and a hit batter in the second inning.

"He got two runners on base and tried to muscle up there and didn't need to," Bell said.

Howell pitched three shutout innings. Brian Bass gave up a run in two innings, working his way out of a bases-loaded jam in the eighth. Andrew Sisco finished with a one-walk ninth.

Silverio OK: Third-base coach Luis Silverio had an X-ray of his left cheekbone on Monday and was pronounced OK.

Silverio was hit Sunday by an errant throw against the Rockies.

Pitcher Ambiorix Burgos was hit by a comebacker on the right forearm in the same game.

"They tell me I can pitch tomorrow but I'm not sure. I know I can pitch two days from now," he said Tuesday.

Single-game tickets: The Royals will begin selling single-game tickets for the regular home season at 9 a.m. CT Saturday.

They are available through the Royals' Web site as well as 1-800-6ROYALS, Hy-Vee Stores and the Kauffman Stadium ticket office.

On deck: The Royals will meet the Milwaukee Brewers at 12:05 p.m. CT Wednesday at Maryville. Right-hander Joe Mays will start against Brewers right-hander Dave Bush. The Royals also will meet Korea's World Baseball Classic team at 6 p.m. CT at Surprise Stadium.