Stewart removed from tonight's lineup, Zimmermann optioned

Removing one player from tonight's Orioles lineup led to a massive shuffling of personnel.

Outfielder DJ Stewart is a late scratch due to stiffness in his lower back. Manager Brandon Hyde said Stewart is receiving treatment and is "kind of day-to-day right now."

When the dust settled, Pat Valaika wound up at second base rather than sitting on the bench among three reserves.

Rio Ruiz moved from second base to third and Maikel Franco is the designated hitter, with Trey Mancini at first base and Ryan Mountcastle in left field. Austin Hays shifted to right field.

Stewart broke an 0-for-21 streak Saturday with a home run in Oakland and singled the following day. He also hit a fly ball in the eighth inning that would have produced a go-ahead RBI except for Ramón Laureano's sensational leaping catch at the fence.

Based on a conversation with Stewart, Hyde said the back soreness isn't related to the weekend collision with the bullpen awning in Oakland. Stewart absorbed the punishment in the right side of his face, but stayed in the game.

Stewart has made nine starts in right field, eight in left field, and one as the designated hitter. He's been the primary replacement for Anthony Santander in right and again is receiving an opportunity to get regular at-bats as long as he's healthy.

The Orioles broke camp with Stewart on the injured list with a strained hamstring. He's batting .188/.288/.313 with two doubles and two home runs in 73 plate appearances.

His day-to-day status leaves the club with two reserves tonight - catcher Chance Sisco and infielder Ramón Urías. It was in the same bind with shortstop Freddy Galvis unavailable due to a sore left adductor/groin.

Here's the new lineup:

Cedric Mullins CF
Austin Hays RF
Trey Mancini 1B
Maikel Franco DH
Ryan Mountcastle LF
Freddy Galvis SS
Pedro Severino C
Rio Ruiz 3B
Pat Valaika 2B

Dean Kremer RHP

Also, the Orioles optioned left-hander Bruce Zimmermann to the alternate site in Bowie and recalled reliever Isaac Mattson, who's waiting to make his major league debut.

The move is similar to the one last month that sent Dean Kremer to the alternate training site. The Orioles can skip Zimmermann's turn, manage the rookie's innings and bring in a fresh arm.

Zimmermann is 1-3 with a 5.40 ERA and 1.633 WHIP in six starts. He hasn't cleared five innings in the last three.

The Orioles are off Thursday and May 13 and can tweak the rotation.

Mattson, acquired from the Angels in the Dylan Bundy trade, is wearing No. 60. The Orioles put him on the 40-man roster to protect him in the Rule 5 draft.

In former Orioles news, the Mets released veteran catcher Caleb Joseph, who signed a split contract. And the Reds signed reliever Brad Brach to a minor league deal.

In lesser news, this is my last post tonight unless there's late-breaking news. But I'm appearing on "O's Xtra" that airs at 9:30 p.m. on MASN2.