He will miss a scheduled start Tuesday night against the Baltimore Orioles.
"He's a DL candidate," general manager Allard Baird said. "We'll make a decision tomorrow."
Harvey, who missed four games because of a back strain, started Friday night against the Tampa Bay Devil Rays. After one at-bat (he struck out) and two innings, Harvey was replaced by Eli Marrero.
A scorching line drive by Aubrey Huff was Harvey's undoing.
"When I made the catch in the first off Huff, I felt something in my back," Harvey said. "I took my at-bat and with every swing, it felt worse. Today my back felt great, then all of a sudden it locked up on me."
Mike Sweeney wasn't available to play first base because he was out with a rib-cage pull. He was on the bench for the second straight night after playing in the 34 previous games.
"He's day by day. He feels better today. We'll see what happens but we're not going to push him in there and lose him for four or five days," interim manager Bob Schaefer said.
"If this was September, he'd probably be playing."
Sweeney's bat had been smoking -- an 11-game hitting streak which included seven home runs and 12 RBIs -- and he was champing at the bit. But the Royals convinced him not to risk a longer-term injury. Sweeney also had an oblique problem in Spring Training but, after a few days' rest, he was OK.
"It's the same thing I had in Spring Training," Sweeney said. "I felt it for the first time in my last at-bat at Toronto (on Wednesday)."
Sweeney hopes to play Saturday or Sunday against the Devil Rays.
Infielder Tony Graffanino, out with a right wrist injury since last Sunday, took live batting practice and should be ready to play soon.
Royals trivia: On May 13, 1976, George Brett set the Major League record for most consecutive games with three or more hits. How many games was it? (Answer below.)
Job opportunity: Sure, Schaefer would like to be selected as successor to manager Tony Pena. No, he's not sending in his resume which general manager Allard Baird knows very well anyway.
"I'm not using this as a trial camp. I've managed before in the Minor Leagues and I've done a lot of things in baseball. I know what it takes to be a manager. I'm just going to do the best for the players and the best for the organization, and whatever happens, happens," Schaefer said.
"I'm going to manage the way I manage. If it fits, it fits. If it doesn't, it doesn't."
Baird said Friday night that he's on schedule with the manager search, nearing the completion of a master list of candidates. Schaefer's name is the only one that Baird has made public.
Minor leaguers suspended: First baseman Josh Pressley and infielder Luis Ugueto were suspended 15 days for violating the policy of the Minor League Drug Prevention and Treatment Program.
Baird said the two players would return to their teams after their suspensions are fulfilled.
"My attitude is to continue to educate and we feel we did a good on-going job beforehand and they made their choice," Baird said. "They're held accountable."
Both players were signed as Minor League free agents last winter. Pressley had been with the Mets, Ugueto with the Mariners.
Pressley was hitting .325 with four homers, 16 RBIs in 31 games for Double-A Wichita. Ugueto had a .213 average with nine RBIs in 27 games, mostly at second base, for Triple-A Omaha.
Trivia answer: Six games. From May 8-13, Brett accumulated 21 hits.
Farm report: Chris George, Steve Stemle and Byron Embry combined for an eight-hit shutout as Triple-A Omaha downed Salt Lake, 3-0, in the first game of Thursday's doubleheader. Calvin Pickering, who had been in a 1-for-24 slump, had two hits including a homer. The O-Royals lost the second game, 2-1.
Mitch Maier and Kila Kaaihue each hit his sixth home run but Class A High Desert lost to Lake Elsinore, 9-4. ... RBI singles by Mario Lisson and Alan Moye pushed Class A Burlington over Lansing, 3-2.
Operation Blessing: Sweeney and catcher Alberto Castillo were among Royals players scheduled to distribute groceries to needy Kansas Citians at 10:30 a.m. Saturday at Indians Springs Shopping Center.
The Royals and NFL Chiefs annually participate in the food distribution of Operation Blessing International. Up to 3,000 persons were expected to receive food packages.
On deck: The Royals will meet the Devil Rays in the third of four games at 6:10 p.m. CT on Saturday at Kauffman Stadium. The first 20,000 fans will receive a Royals powder blue trucker cap from Dodge.