MIAMI -- A's catcher Derek Norris exited Friday's game against the Marlins in the bottom of the fourth inning with lower back tightness.
Norris is considered day to day, and the catcher believes he could be back in the starting lineup as soon as Sunday.
"I feel all right. I just tweaked it," Norris said after the game, a 9-5 Oakland win. "Anybody that has back problems knows they can come out of nowhere. My muscles aren't spasmed out or anything like that. I wouldn't suspect anything more than about a day off or so.
"My pain tolerance is high. It requires quite a bit for me to not be able to play."
Norris has a history of back issues, but he has never missed significant time. He was replaced behind the plate by Stephen Vogt, who went 2-for-3 with an RBI.
All-Star hopeful Cespedes thriving in three-hole
MIAMI -- After spending the majority of the first two months of the season alternating between the fourth and fifth spot in the A's lineup -- all the while battling inconsistency -- Yoenis Cespedes has found his groove in the three-hole.
That's where he was again for Friday's three-game series opener in Miami, where the A's last played in 2003. It's also near the offseason home of the Cuban slugger, who resides an hour north in Boca Raton during the winter months.
Cespedes entered the day riding a 10-game hitting streak, having gone 14-for-39 in that span, and he extended it to 11 games with two more hits in the 9-5 victory over the Marlins, including the go-ahead RBI single in the ninth. He's batted third in 12 of his last 13 games, and is hitting .413 in that spot.
He's hitting just .248 from the fifth hole and .250 in the cleanup spot.
The All-Star hopeful, batting .272 overall with 14 homers, is currently ranked fourth among American League outfielders in voting.
Fans can cast their votes for starters at MLB.com -- online or on a mobile device -- using the 2014 All-Star Game MLB.com Ballot Sponsored by Experian until Thursday, July 3, at 8:59 p.m. PT. The 2014 All-Star Game will be played at Target Field on Tuesday, July 15 on FOX.
• Rehabbing lefty Eric O'Flaherty gave up a pair of runs on two hits and a walk with one strikeout in two-thirds of an inning for Triple-A Sacramento on Thursday. It marked his seventh appearance with the River Cats, and he's expected to make one or two more before joining Oakland's roster.
"You like to see him better toward the end, but when you're talking about a guy coming off Tommy John [surgery], we're mostly looking for health," said manager Bob Melvin. "We'll get some input from pitching coaches how the ball's coming out of his hand, but you'd like to have him come back with a couple good outings where he feels good about the results."
Jane Lee is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.