No competitor likes to be sidelined, Kyle Gibson said, no matter the circumstances. That said, the Twins pitcher understands team officials do not want to hurry his return as he recovers from stiffness in his lower back.

Gibson will miss Saturday's scheduled start against the White Sox at Target Field. Friday, the team recalled lefty Logan Darnell from its Class AAA affiliate in Rochester to fill in for Gibson in the third game of the series. Darnell will get his first major-league start after spending a bit of time with the Twins earlier this season.

Manager Ron Gardenhire said Gibson felt much better Friday, when he did some light throwing off the mound. But Gibson will not throw a bullpen session until Saturday at the earliest, and Gardenhire did not want to use him without seeing him demonstrate his readiness. If Gibson continues to progress, Gardenhire said, he anticipates him returning to the rotation for a Tuesday start at Kansas City.

"This is a young pitcher we think the world of," Gardenhire said of Gibson, who is 8-8 with a 4.19 ERA. "We're going to make sure we do everything right as far as [his recovery] goes."

Late Thursday, Gibson said his back still is sore, but it feels similar to the discomfort he typically experiences early in spring training. He has been doing shoulder exercises daily to ensure his strength does not wane while his back heals.

Darnell made one appearance in relief during an early-season stint with the Twins, impressing General Manager Terry Ryan with three scoreless innings against Cleveland. In 17 starts with Rochester, he is 5-5 with a 3.43 ERA. "It helps that I've gotten people out before up here," Darnell said. "But I still have to go out there and do what I've always done."

To make room for Darnell on the roster, the Twins optioned infielder Jorge Polanco to Class AA New Britain.

Hughes OK

A day after pitcher Phil Hughes was drilled by a shot off the bat of Adam Dunn, Gardenhire said Hughes is not expected to miss his next start. Hughes was struck in the right shin in the fourth inning Thursday, and he feared he might have broken a bone. X-rays showed no sign of serious damage, and the injury is described as a contusion.

"He's sore, which was expected,'' Gardenhire said. "But it's not as bad as he thought."

Coaching carousel

With coach Paul Molitor spending the weekend in Cooperstown, N.Y. at the Baseball Hall of Fame induction weekend, the Twins had to call up a fill-in. Sam Perlozzo, the team's minor-league infield and baserunning coordinator, will coach first base while Molitor is away.

Molitor had been coaching first base in place of Scott Ullger, who was moved to the third-base spot in the absence of Joe Vavra. Vavra recently was diagnosed with a torn labrum in his hip. He will need surgery, and though doctors have said he will not risk further injury if he puts it off, Gardenhire has recommended that Vavra have the procedure now.

"There's not a better time to get it done," Gardenhire said. "You get all the rehab right here."

Perlozzo is in his first season with the Twins organization, but Gardenhire knows the former Baltimore manager well. During Gardenhire's days in the Mets' system, Perlozzo was his roommate and his manager.

Etc.

• Several Twins players and officials said they will miss designated hitter Kendrys Morales, who was traded Thursday to Seattle. While Ryan admired his work ethic, Gardenhire mentioned his positive attitude — and another quality. "Great guy," he said. "Got really good cigars."

• A glass case at Target Field that on Thursday held memorabilia from Chuck Knoblauch had its exhibit switched Friday to All-Star Game items. Knoblauch's scheduled induction into the Twins Hall of Fame was canceled Thursday after the former All-Star second baseman was charged with assaulting his ex-wife in Houston.

• Joe Mauer (strained right oblique) took soft toss in the batting cage Friday and said his rehabilitation program remains on track.