Chicago Cubs slide into home stretch

The Cubs are scuffling heading into Arizona Friday night for a crucial three-game series against the Diamondbacks, who are just two games behind the North Siders for the second wild card spot.

Why it matters: The playoff race is tightening up after the Cubs lost a tough series against the lowly Rockies in Colorado.

Flashback: Before that, the Diamondbacks took three of four games at Wrigley Field.

• The Cubs still hold a wild card spot, but the final 15 games feature series against tough contenders: the Diamondbacks, Braves and Brewers.

Zoom in: The team was uncharacteristically sloppy in Colorado, making base running mistakes and defensive lapses, while stranding several runners.

• The Rockies are currently the worst team in the National League.

Yes, but: The Cubs may be catching the Diamondbacks at the right time. They just lost three straight games to the Mets.

Reality check: They aren't just fending off the Diamondbacks down the stretch; the Cincinnati Reds and the San Francisco Giants are also within striking distance.

Injury update: Closer Adbert Alzolay is on the injured list with a forearm strain, but he is eligible to return for the last six games if healthy.

State of play: Since Aug. 1, the Cubs lead the major leagues in one-run victories, which means the team needs a reliable 9th-inning reliever.

The bottom line: If you were waiting to watch the Cubs, the time is now.

• The Cubs send Cy Young candidate Justin Steele to the mound for the first game. The ace leads all of baseball with a 2.49 ERA.