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."
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.