CHICAGO -- The Chicago Cubs return to Wrigley Field on Friday with a shored-up starting pitching staff and their longest winning streak of the year.
The defending World Series champions have won six straight since the All-Star break and are only one game out of first place -- a 4 1/2 game pickup on the National League Central-leading Milwaukee Brewers -- as they open a three-game weekend series with division rival St. Louis (46-49).
Chicago (49-45) will also show off its newest acquisition -- left-hander Jose Quintana -- with a Sunday start in his Cubs home debut.
"We've had this energy since the beginning of the second half in Baltimore," manager Joe Maddon said Wednesday after the Cubs' 8-2 victory over the Braves in Atlanta. "I'm feeling the guys more mentally involved, and I love that."
Martinez, who pitched two innings in last week's All-Star Game, makes his 22nd career appearance (12th start) against the Cubs. He is 4-3 with a 4.16 ERA against Chicago.
Martinez is 1-0 in two starts vs. Chicago this season, most recently tossing 6 2/3 innings against the Cubs while striking out seven in a 5-3 victory on May 13. He needs one strikeout to reach 600 for his career.
Arrieta makes his 20th start of the season but only his seventh at home. He is 8-3 with a 2.00 ERA all-time against St. Louis, including 6-1, 0.95 at Wrigley Field. He is 1-1 this season in two starts against the Cardinals, both at Busch Stadium.
Arrieta allowed two runs (one earned) in 6 2/3 innings Saturday in a 10-3 victory over the Orioles, his ninth quality start.
Arrieta's performance is part of a recent trend of improved Cubs starting pitching.
Quintana, acquired in a trade with the Chicago White Sox, tossed seven shutout innings Sunday in his Cubs debut.
On Wednesday, Mike Montgomery took a no-hitter into the fifth inning and allowed two hits in a six-inning performance for an 8-2 win at Atlanta.
Moreover, right-handed starter Kyle Hendricks rejoined the club after a six-week stay on the disabled list caused by tendinitis in his pitching hand. He tossed five perfect innings in a Monday rehab outing at Double-A Tennessee.
St. Louis is 4 1/2 games behind Milwaukee and is 3-4 on its current road trip -- including a 3-2 Thursday loss as the New York Mets rallied with single runs in the eighth and ninth.
"Today would have been a great opportunity to win this series," Cardinals infielder Matt Carpenter said. "When you lose by beating yourself, that's when it leaves a sour taste in your mouth, and today that's exactly what happened."
Cubs third baseman Kris Bryant's status is uncertain for the Friday game after he sprained his left pinkie finger Wednesday. Bryant caught the foot of Atlanta's Johan Camargo while sliding head-first into third base.