Win No. 15 has eluded Chris Tillman for four starts now, but that is through absolutely no fault of his own. The Orioles right-hander has posted a 2.57 ERA and a 0.86 WHIP in those four contests.
"We count on him every fifth day to go out there and give us the performances that he's been [giving]," said Baltimore center fielder Adam Jones. "Nothing but praises for him right now. He's been throwing the ball lights-out."
Tillman (14-4, 3.66 ERA) will get his fifth crack at his 15th win on Thursday in a pivotal division matchup against the American League East-leading Red Sox.
After dropping the first two games of the series, Baltimore now sits 4 1/2 games back of the A's for the second AL Wild Card spot and 7 1/2 back of Boston in the AL East.
Left-hander Jon Lester gets the ball for the Red Sox, looking to build on a recent hot streak. Lester's last four starts have all been quality, and his last two were among his best this season.
Lester tossed 8 1/3 shutout innings in San Francisco on Aug. 19 before he threw 7 1/3 innings of three-hit ball, allowing one run on Saturday in Los Angeles.
"He's just getting more comfortable," Red Sox catcher Jarrod Saltalamacchia said. "I think he was messing with mechanics a little bit and going back and forth with different stuff, as we all do. The biggest thing for him is getting ahead, first-pitch strikes and focusing on attacking the strike zone."
Lester (12-7, 3.97 ERA) will have to deal with an Orioles offense that leads the league in home runs with 177. The O's hit two more on Wednesday and are on pace for 218 this season -- which would be the second most in franchise history. (They hit 257 in 1996.)
But the Orioles are also second in baseball in home runs allowed -- one behind Toronto. No team has finished a season first in homers and homers allowed since the 1950 Brooklyn Dodgers.
Orioles: Gausman recalled
Top prospect Kevin Gausman was recalled from Triple-A Norfolk on Wednesday, and the Orioles said that he will pitch out of the bullpen.
"Tonight we look at him as a reliever, but in the future, we still think he is going to be a good starter for us," said manager Buck Showalter. "But you never know what path your career takes down the road."
Gausman is 1-3 with a 6.21 ERA in nine appearances for Baltimore this season.
Red Sox: Bogaerts makes first Fenway start
Xander Bogaerts, the club's No. 1 prospect, made his first start at Fenway Park on Wednesday night, going 0-for-3 while playing third base.
"The early work was critical in him getting comfortable over there," manager John Farrell said of Bogaerts' move to third. "But he's such a good, athlete and he's got that internal clock that we saw."
• The Orioles have committed just 39 errors through 131 games this season. The 2003 Mariners hold the current single-season record for fewest errors with 65.
• The Red Sox and Orioles have split 12 games this season, with Boston having won three of five at Fenway Park.
• The Red Sox have won a Major League-leading 27 series this year.
• Orioles catcher Matt Wieters is hitting .359 with three doubles and a triple in 39 at-bats against Lester.