PITTSBURGH — Salvy Perez provided the Royals with some positive buzz on an otherwise dismal Friday night by catching all nine innings on a rehab assignment at Class AAA Omaha while going five for five in an 11-5 victory over Round Rock.

As to the inevitable question — how soon can he return to the big-league lineup? — the Royals are urging caution. Friday was Perez’s first game behind the plate outside of extended spring training since suffering torn cartilage March 13 in his left knee.

“I’m not sure yet,” general manager Dayton Moore said. “Obviously, it’s predicated on the medical evaluation more than the on-field performance. It’s a day-to-day thing when guys are going through rehab. It’s just hard to predict. You can’t rush it.

“The healing process is what it is, and those mechanisms are put in place for a reason from years and years of research and with the expertise of doctors, trainers and physical therapists. You’re certainly not going to see him this week.”

The Royals anticipated Perez, 22, would require most or all of the 20 days permitted for non-pitchers on rehab assignments to provide an adequate test for his recovery.

That hasn’t changed.

“It’s just like somebody who gets Tommy John surgery,” Moore said. “They might be feeling great, but there’s still a recommended recovery time based on lots or research and the history of players (returning from the injury).

“You’ve just got to play it out from a medical standpoint.”

As it is, Perez is already on track to return by late June — or roughly three weeks ahead of the original timetable.

Paulino to disabled list

Right-hander Felipe Paulino will require another trip to the disabled list, it turns out, in order to recover from a strained right groin that forced his departure last Wednesday in the first inning against Minnesota.

The Royals made the decision after determining he was likely to miss at least two starts. Right-hander Nate Adcock returned from Omaha to fill the roster vacancy.

“We wanted to give Paulino a couple of days to see if he could get better,” manager Ned Yost said. “We knew he wouldn’t make his next (scheduled) start, and it now is doubtful that he could make the start after that.”

Paulino, 28, opened the season on the disabled list because of a strained right forearm. He returned May 5 and went 3-1 with a 1.67 ERA in seven starts prior to his latest injury.

Adcock, 24, is back for the fourth time since the season started. He was 0-3 with a 3.74 ERA in six games, including two starts, in his previous three tours.

“Right now, he’s a long guy,” Yost said. “We may adjust later.”

Paulino’s injury pushes the Royals’ list of disabled players back into double figures — seven players on the 15-day list and three players on the 60-day list.

Cain suffers setback

More bad news: Outfielder Lorenzo Cain is returning to Kansas City from the club’s complex in Surprise, Ariz., to undergo a new medical examination in hopes of determining the reason for his slow recovery from a torn left hip flexor.

“We’re reevaluating him because he wasn’t progressing,” Moore confirmed. “He’s going to be in Kansas City this week, and we’ll look to get him going again on Wednesday.”

Asked whether Cain might require further surgery, Moore said: “I don’t think so, but I don’t know yet.”

Cain, 26, suffered the injury April 24 while on a rehab assignment at Class AA Northwest Arkansas for a strained left groin. The groin injury occurred April 10 in Oakland when he slammed into the center-field wall after making a catch.

Duffy surgery set

Lefty Danny Duffy has a new date — Wednesday — for an operation to repair a torn ulnar collateral ligament in his elbow. The procedure is commonly known as Tommy John surgery.

The operation, previously planned for May 31, was postponed when Duffy contracted strep throat. Dr. Lewis Yocum will perform the procedure in Los Angeles. Typical recovery time is 10-14 months.

Duffy, 23, was diagnosed with the ligament tear after exiting a May 13 start in Chicago because of elbow pain.

The Royals should see whether Yocum offers volume discounts because Duffy in their third pitcher this season to undergo the procedure. Joakim Soria had it on April 3, and Blake Wood had it on May 25.

More rehab updates

Second baseman Chris Getz and left-handed pitcher Jonathan Sánchez appear likely to return from rehab assignments at Omaha within the next week. Getz should be ready by Tuesday’s series opener against Milwaukee at Kauffman Stadium.

“Probably,” Moore said. “He’ll probably stay there through the weekend unless something unforeseen happens.”

Getz is recovering from a bruised left ribcage suffered May 16 in a collision at first base with Baltimore’s Chris Davis. Getz aggravated the injury May 21 on a slide at second base in New York. He is three for seven with a walk in two games at Omaha.

Sánchez permitted three runs and five hits in five innings Friday against Round Rock in his third rehab start in his recovery from biceps tendinitis, which was diagnosed after a May 7 loss to Boston.

“He pitched OK,” Moore said. “His line was fine. The scouts who were there said he threw the ball fine.”

Sánchez could pitch as soon as Wednesday on normal rest, but the Royals won’t require a fifth starter until next Saturday at St. Louis. Sánchez has allowed 10 runs and 14 hits, including five homers, in 131/3 innings over three rehab starts.

Honoring Hosmer

Class AA Northwest Arkansas gave away Eric Hosmer bobblehead dolls to the first 2,000 fans through the gates Saturday night for its game against Arkansas at Arvest Ballpark.

Hosmer batted .313 with 13 homers and 35 RBIS in 50 games for the Naturals in 2010 but had a big postseason in helping them win the Texas League championship.

Minor details

Center fielder Wil Myers had two more hits Friday night at Omaha in his continuing push for promotion. Myers boosted his average to .325 by going two for five. He also has eight homers and 23 RBIs in 22 games since his promotion from Northwest Arkansas.

Myers, 21, is batting .336 overall this season in 57 minor-league games with 21 homers and 53 RBIs. He has a .398 on-base percentage and a .728 slugging percentage.

Looking back

It was six years ago Sunday — June 10, 2006 — that outfielder Reggie Sanders became just the fifth player in major-league history to reach 300 homers and 300 stolen bases in his career.

Sanders got his 300th career homer against Chad Harville in the eighth inning of a 9-5 loss to Tampa Bay at Kauffman Stadium. The previous members in the 300-300 club were Willie Mays, Bobby Bonds, Andre Dawson and Barry Bonds.

Steve Finley and Alex Rodriguez have joined the list since Sanders. Former Royals outfielder Carlos Beltran needs one more stolen base to become to eighth player to achieve the double milestone.

Sanders, now 44, concluded a 17-year career spent with eight teams in 2007 with the Royals. He finished with 305 homers and 304 stolen bases.