It is the second time this season the 43-year-old Johnson has
been on the disabled list. He started the year on the DL while
recovering from offseason back surgery.
He will be replaced on the roster by right-hander Enrique
Johnson felt tightness in his buttocks muscle while playing
catch, Arizona manager Bob Melvin said. He was scheduled to pitch
against the Baltimore Orioles on Saturday, but was scratched before
the game Friday night.
Johnson is 4-2 with a 3.52 ERA and 70 strikeouts in nine starts
this season. In his last outing, he allowed one run and four hits
in six innings in a win over Boston.
Edgar Gonzalez will start for Arizona on Saturday. He pitched
three innings of relief on Wednesday against the Yankees.
"We'll run a 65-, 70-, 75-pitch count for him depending on how
he feels when he goes out there tomorrow," Melvin said.
Meanwhile, the Diamondbacks optioned outfielder Alberto Callaspo
to Triple-A Tucson and purchased the contract of infielder Augie
Ojeda from Tucson. To make room on the 40-man roster, the club
designated pitcher Mike Schultz for assignment.
Ojeda was batting .323 in 32 games with Tucson.
"He had a great spring for us. He'll play any position; he's
always prepared to play," Melvin said. "He's one of those guys on
the bench, especially on a National League team, that's invaluable.
"It's nice to have a guy like Augie here. You reward a guy for
not only playing well, but for preparing and working hard."
Ojeda homered and made two fine plays at second base in
Arizona's 7-3 win over Baltimore on Friday night.