BALTIMORE -- Starter Zach Britton is getting closer to a return with the Orioles, after he was put on the 15-day disabled list Friday with a left shoulder strain. The rookie southpaw threw long toss for the first time in six days on Wednesday and is scheduled to make a rehab start either on Sunday for Double-A Bowie or Monday with Class A Frederick.

"Right now, [Britton is] tentatively scheduled to pitch Sunday," Orioles manager Buck Showalter said. "But we've got a wiggle day there. The problem is if he pitches on Monday, [pitching coach] Rick [Adair] actually talked about maybe taking two work days. If he does that, then he'd pitch Monday and that would have to be in Frederick."

Britton, who holds a 6-9 record with a 4.66 ERA, has responded well to anti-inflammatory medication. If the rest of his recovery proceeds without complication, Britton could return to the starting rotation against the Angels next week. Left-hander Jo-Jo Reyes made a spot start in place of Britton on Tuesday night and is scheduled to do so again on Sunday against the Tigers.

The 23-year-old Britton will attempt another session of long toss on Thursday.

Reynolds turning a corner with glove

BALTIMORE -- Earlier this season, Mark Reynolds couldn't seem to match his power at the plate with consistency at the hot corner.

The Orioles' third baseman, who was tied for the sixth-most home runs in baseball with 26 entering play Wednesday, had also committed one fewer error than Rangers shortstop Elvis Andrus, who leads the Majors with 22.

But Reynolds' defense has turned a corner. The Orioles' offseason acquisition made just one error in his previous 33 games, and his diving play in the third inning on Tuesday to snag a Paul Konerko line drive made it onto SportsCenter's Top 10 plays.

"One of the line drives Mark caught last night, that's as good as I've seen him off the mark all year, no pun intended. ... Mark, he's in a good place physically right now," Orioles manager Buck Showalter said.

Reynolds was recently moved to first base for four games against Toronto and Chicago earlier this week and his play proved to be consistent from the other side of the diamond. The 27-year-old's miscues in the field earlier this year quickly eclipsed his error total from last season, when he committed 18 for the D-backs.

With Orioles starting first baseman Chris Davis back to health, Reynolds is still in danger of breaking the franchise record for most errors in a season by a third baseman, as his next miscue will tie Brooks Robinson's 22 in 1958. But Reynolds is also on pace for a more positive franchise mark. He needs just five more homers to tie Tony Bautista for the most home runs in a season by an Orioles third baseman.

Slumping Vlad takes a night off

BALTIMORE -- Vladimir Guerrero was out of the Orioles' starting lineup for the first time in 15 games on Wednesday. In his place, outfielder Nolan Reimold got the nod as designated hitter against the White Sox, batting eighth instead of Guerrero's usual cleanup spot, which was filled by Adam Jones.

Manager Buck Showalter said before Reimold's walk-off homer in the 10th gave the Orioles a 6-4 win that he wanted to give the 36-year-old Silver Slugger Award winner a day to rest and that Guerrero would be starting in his usual role for the series finale on Thursday.

"It's just one day," Guerrero said. "I'll be back in there tomorrow."

Guerrero, who was placed on the 15-day disabled list from July 17-26 with a fractured right wrist, said "everything is fine" physically.

Although Guerrero is back to health, his performance has drawn concern from fans. Entering Wednesday, the nine-time All Star had gone 5-for-31 (.161) in August, as his average continues to dip from .290 on June 18, to its present .274 mark.

Guerrero, who ranks fourth among active all-time home run leaders, may get his chance to turn things around on Thursday against White Sox left-hander Mark Buehrle. In his career, Guerrero has batted .325 with four home runs against Buehrle.

Along with his .274 average, Guerrero has nine home runs and 36 RBIs. The worst season the slugger has had at the plate within the last decade came as a member of the Angels in 2009, when he hit .295 with 15 homers and 50 RBIs.

Tidbits

• Orioles right-hander Jake Arrieta will undergo season-ending surgery to remove the bone spur in his right elbow on Friday in California. The procedure has been a near certainty since Arrieta was put on the disabled list on Aug. 1, and it was reaffirmed after he had a CT scan and MRI arthrogram (which involves contrast dye) with noted orthopedic surgeon Dr. Lewis Yocum in Los Angeles on Wednesday. The full recovery period is 2 1/2 months, and Arrieta is expected to have a normal offseason throwing program and be ready to go for the start of Spring Training.

• The Orioles have agreed to terms with 42nd-round Draft pick, right-handed pitcher Jason McCracken. Baltimore has agreed to terms with 18 of its 50 Draft picks.

• Cesar Izturis (left groin strain) traveled to Sarasota, Fla., on Wednesday for a rehab stint in extended spring training.

• Right-handed pitcher Brandon Erbe cleared waivers on Wednesday and was outrighted to Class A short-season Aberdeen.