A look at what's happening all around the majors Saturday:
PAIR OF ACES
A pitching showdown at Wrigley Field as Cubs right-hander Jake Arrieta (16-5, 2.84 ERA), the NL leader in wins, faces Giants lefty Madison Bumgarner (13-8, 2.49). A tight game may not bode well for the Giants, who are 4-12 in one-run decisions since the All-Star break.
ON THE MEND
Dodgers ace Clayton Kershaw is scheduled to throw three innings or about 50 pitches during a rehab outing for Class A Rancho Cucamonga, with left-hander Brett Anderson to follow. Anderson is on the disabled list with a finger blister. Kershaw has been sidelined since late June with a herniated disk in his back.
In a pivotal AL Central series between surging playoff contenders, Miguel Cabrera and the Tigers visit Kansas City. Detroit rookie Michael Fulmer (10-5, 2.69 ERA) starts on six days' rest against Yordano Ventura (9-9, 4.33) and the World Series champion Royals.
Leading the big leagues in wins, Boston right-hander Rick Porcello (18-3, 3.26 ERA) tries to move within one of No. 20 when the Red Sox visit last-place Oakland. Porcello recently became the first Boston pitcher in 70 years to start a season 13-0 at Fenway Park, but this time he'll take his act on the road.
Rookie right-hander Joe Musgrove starts for wild card-hopeful Houston in the middle game of three at AL West-leading Texas. Cy Young Award winner Dallas Keuchel was bumped out of the series for extra rest. The left-hander is set to start Tuesday in Cleveland as the Astros open September with 13 consecutive games against current division leaders (Texas in two series, Cleveland, Chicago Cubs).
The Yankees hope for good news on rookie right-hander Chad Green, who left Friday night's start in Baltimore with right elbow pain. He was scheduled to be examined by a doctor Saturday, the team said.