D-Backs fire hitting coach Seitzer

Rick Schu will rejoin the Diamondbacks today, but Randy Johnson’s return is far more problematic.

Schu will replace Kevin Seitzer as the D-Backs’ hitting coach, a quick reaction to a somber first half in which the D-Backs rank in the lower third of most NL offensive categories, including 15th in batting average (.248) and 12th in runs and OPS, a statistic that combines on-base percentage and slugging percentage.

Johnson, meanwhile, took a third epidural in his lower back Friday and will be eased into his throwing program during his third stay on the disabled list this season.

Johnson is eligible to return Saturday, “but it is not going to be close to that,” said general manager Josh Byrnes, although he would not go as far as to say Johnson will be out until August.

“There are competing things — you give him time off to alleviate the symptoms, and you need more time to build your arm back up,” Byrnes added.

Yusmeiro Petit will remain in the starting rotation in Johnson’s place.

Schu, the D-Backs’ hitting coach in 2004, was a candidate, along with Dave Hudgens, for the D-Backs’ hitting coach position when Seitzer was hired this winter. Schu also was a finalist in Colorado in the offseason.

Schu, 46, brings a hands-on knowledge regarding most of the franchise’s young hitters after spending four of the last five seasons as the roving hitting instructor.

“Without picking on individuals, we can do better than this,” Byrnes said.

The D-Backs struggled to get on track early in the season and except for a few brief streaks never mounted much offense.

Byrnes and manager Bob Melvin began seriously considering a change during the D-Backs’ recent 2-8 road trip, when it scored only 29 runs and were 12-for-72 with runners in scoring position against sub-.500 teams San Francisco, St. Louis and Cincinnati.

Especially struggling were the younger D-Backs, around whom the franchise is building its future.

Young guns Stephen Drew, Miguel Montero, Carlos Quentin and Chris Young are all hitting below .250, and Quentin was optioned to the minors last week when his average dipped to .210.

“Obviously we expect a lot of those guys, and a lot of them have struggled,” Byrnes said. “Looking back, facing so much of our early season facing good pitching started us in a slump that we never really got out of. Rick has a lot of history with these guys.

“We feel a different voice will be helpful to get them turned around.”

Seitzer, a two-time All-Star, had worked as a private hitting instructor since retiring after a 12-year major league career in 1997.

Schu spent parts of nine seasons in the majors and has been with the D-Backs since their inception in 1998, serving as a coach in South Bend, Lancaster and Tucson before becoming a roving hitting instructor.