Buckner was 3-2 with a 2.89 in five starts with Triple-A El Paso. He signed with the team on April 19 after not being with a team in Spring Training.
The team had considered giving right-hander Donn Roach a second start, but felt it might need him in relief Friday since Tim Stauffer, who like Roach is a long reliever, is being pressed into a start after pitcher Robbie Erlin developed soreness in his left elbow.
In the past week, Andrew Cashner and Erlin developed elbow soreness. Roach made a start last Sunday for Cashner and Stauffer takes over the Erlin on Friday.
Buckner has appeared in 43 games over the past four seasons with four teams and has made 23 starts with the Royals, D-backs and Angels. Manager Bud Black likes his experience.
"He's done this before. His experience, in his career, popping him in there, mentally we won't have any issues," Black said.
Corey Brock is a reporter for MLB.com. Keep track of @FollowThePadres on Twitter.Will Laws is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.