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8/10/2013 5:55 P.M. ET

Norris gets three hits but leaves with back spasms

TORONTO -- Derek Norris enjoyed the first three-hit game of his career in Saturday's 5-4 loss to the Blue Jays. But what should have been a pleasant day ultimately ended in pain because of lower back spasms.

It was the fourth at-bat when Norris felt his back tighten, forcing Bob Melvin to pinch-hit Stephen Vogt for him in the ninth inning.

Norris was seen moving extremely slow around the clubhouse after the game, visibly hurting. But he assured reporters "it looks worse than it is."

"Just kind of one of them things," Norris said. "I'll be fine. Just some treatments should take care of it, get it back to normal. To my knowledge, I'll be ready to go tomorrow. Starting or not, we'll see how it goes tomorrow. I don't plan on missing any time from this, but we'll just see how it feels."

An offensively-challenged A's club can't afford to lose Norris, who is batting .372 since the start of July -- especially since they're already without John Jaso (concussion).

"He's been swinging the bat well against left-handed pitching," Melvin said about Norris. "It's a spot right now we can move around a bit. We're trying to get our best bats against left-handed pitching right now.

"You get your righty or lefty killer an extra at-bat."

Norris hit .283 in April and a combined .163 in May and June.

"It's about where his focus is," Melvin said. "He's not trying to do too much, he's not trying to pull everything. He's using the whole field, and his numbers here recently, especially against left-handed pitching, have been very good."

Rosales designated, rollercoaster ride continues

TORONTO -- For the third time in 11 days, roving infielder Adam Rosales was designated for assignment, his most recent departure necessary to make roster room for Saturday's starter, Sonny Gray.

"He understands, he knows the drill, has been through it," manager Bob Melvin said. "But he really expressed to me that he wants to stay in this organization."

The feeling is mutual.

When the A's initially designated Rosales on July 31, they hoped he would clear waivers. However, the division foe Rangers picked him up, only to also designate him three days later. Oakland claimed him on Thursday, partly as insurance for Alberto Callaspo, who suffered a left forearm contusion the day before, but mostly because they wanted him in the organization all along.

This time around, the A's are more hopeful he gets through waivers, with a multitude of players crowding the wire now that the non-waiver Trade Deadline has passed.

"We hope to get him through quickly and get him back in the organization," Melvin said. "At the very least, if he stays with us, he comes up in September, and who knows? He's been up and down a little bit before to help us. He's just a good fit for us in our organization."

Rosales, 30, hit .191 with four home runs and eight RBIs in 51 games this season in his three stints with the A's, who value his defense above anything else.

Worth noting

• Fresh off a three-homer night on Friday, Josh Reddick was bumped from the seventh to the eighth spot in the batting order. He continued his torrid hitting with a two-run homer in his first at-bat and a solo shot in the ninth for his fifth home run in two days.

"Three homers and move down a spot. Tough league," Melvin joked before the game.

But it wasn't a tough decision for Melvin, not with a tough lefty like Buehrle going for the Blue Jays.

• The A's next win will be the 700th of Melvin's managerial career. He has compiled a 699-678 record in 10 seasons, including an impressive 206-170 mark since taking over the A's on June 9, 2011. That is the eighth best record in baseball over that span.

Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.