"Mike Aviles is going to have Tommy John [elbow ligament replacement] surgery a week from today," Hillman said. "Dr. [Lewis] Yocum will be doing it in L.A. We came to this conclusion after further testing. Obviously, there is ligament damage."
Aviles has been on the disabled list since May 23 with what was described as a right forearm strain. Hillman said the strain was a result of the elbow damage.
"It's definitely disappointing," Aviles said, "but I know something's wrong there because it wasn't getting any better. When I got a second opinion, that's when we found the tear. But it's a double-edged sword. I'll be healthy at the end of it, and I know what I'm capable of doing when I'm healthy."
After giving the elbow a period of rest, the problem did not calm down and surgery was deemed necessary.
"Typical with position players, there's a nine-to-12 month recovery period," Hillman said.
That means Aviles would, at a minimum, be out until some time in mid-March.
"I can be ready to play games in Spring Training next year," Aviles said. "That's the whole reason for getting the surgery as quick as possible, so I can get on the rehab side of it and get back to normal."
The Royals have been relying on Willie Bloomquist for most games at shortstop since Aviles left. He's started 20 games there. Tony Pena Jr. and Luis Hernandez also have seen duty there, starting 12 games each. Hernandez was in the lineup on Wednesday.
Aviles has been in Arizona going through an injury rehabilitation program. He played 36 games this season and batted just .183 with one home run and eight RBIs.
Although he had the problem during Spring Training, he didn't reveal it to the training staff until after the season began, and he obviously was having problems batting and in the field.
Aviles arrived in Kansas City from Triple-A Omaha in late May 2008, and in June he became the regular shortstop, taking over from the slumping Pena. Aviles batted .325 in 102 games, whacked 10 homers, drove in 51 runs and was named the Royals' Player of the Year.
"That's very discouraging when a guy's our Player of the Year last year after winning the shortstop job and battling his rear end off in the Minor Leagues for seven or eight years to get here," Hillman said. "It's impactful news, not only to him, but to us as well."
Aviles actually was in the Minors for six years, but it was a long struggle for him, overcoming the tag of a utility player to finally become a regular and prove he could perform well enough defensively at shortstop.
Certainly he could hit, as his .336 average last year at Omaha and his subsequent success with Kansas City proved.
Aviles is the second regular declared out of the season. Center fielder Coco Crisp is finished after undergoing shoulder surgery. He played 49 games.
In addition, third baseman Alex Gordon was stopped after seven games to undergo hip surgery. He's expected back after the All-Star break.
Catcher John Buck, who became the backup to Miguel Olivo, is rehabbing from a back problem with Omaha. He's expected to return late this week or early next week.
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.