BOSTON -- Catcher John Buck, happy and relieved, rejoined the Royals on Monday at Fenway Park.

He spent the past three days in Kansas City with his wife, Brooke, and their newly arrived twin sons, Cooper and Brody. The boys arrived about a month early, so there were anxious moments for the parents.

"Everybody's good," Buck said after showing baby photos to his teammates. "They're doing well and the scares are over."

Brooke Buck might be able to leave the hospital on Tuesday, but the twin boys will remain there for a time.

"But they're both doing really good right now," Buck said.

Catcher Matt Tupman, called up for the weekend series in Florida, where he singled in his only at-bat, was optioned to Triple-A Omaha before Monday night's game against the Red Sox.

Miguel Olivo was the starting catcher, as manager Trey Hillman decided not to rush Buck back into the lineup.

"We'll use him if we have to," Hillman said. "He's been sitting idle for three days. I don't want to do anything that's counterproductive."