D-BACKS MATCHUPS

Astros at Diamondbacks,

6:40 p.m, YurView AZ Diamondbacks RHP Zac Gallen (17-8, 3.49) vs. Astros RHP J.P. France (11-6, 3.83).

At Chase Field: Gallen might not have made this start had the Diamondbacks clinched on Thursday, but he will since they still need to punch their ticket for the postseason. … Gallen threw well in New York in his most recent start, giving up just three hits and two walks in six scoreless innings. He struck out eight and elicited 13 swinging strikes, the most in a start since July 26. … In four career starts against the Astros, Gallen has a 3.24 ERA. Most recently, he faced them last season, giving up two runs in seven innings. … France, a 14th-round pick out of Mississippi State, was a fairly unheralded prospect, ranking among the Astros Top 30 prospects per Baseball America just once, coming in at No. 21 prior to this year. … He has been a fairly reliable member of the rotation since joining it in May, logging at least five innings in 19 of 23 starts. … He has not been especially sharp in recent starts, posting a 5.75 ERA with 13 walks and 15 strikeouts in 201⁄3 innings in September.

Coming up

Saturday: At Chase Field, 5:10 p.m., Diamondbacks RHP Merrill Kelly (12-7, 3.38) vs. Astros RHP Justin Verlander (12-8, 3.32).

Sunday: At Chase Field, 12:10 p.m., Diamondbacks RHP Ryne Nelson (8-8, 5.35) vs. Astros RHP Cristian Javier (9-5, 4.67).

What to know about the Houston Astros

The Astros are the reigning World Series champs but things have not come so easily for them this year. They spent the bulk of the year in second place in the American League West, which is where they are today despite spending a little time atop the division earlier this month. After a miserable series against the Royals last weekend, they bounced back this week by taking two of three from the Seattle Mariners, whom they lead by 1 1/2 games for the third and final wild-card spot in the AL. The Astros still have a dangerous team, particularly on offense, with DH Yordan Alvarez (31 homers, 1.001 OPS), RF Kyle Tucker (29 homers, .884 OPS) and 2B Jose Altuve (.316 average, .934 OPS) leading the way. They have dealt with a number of injuries to their pitching staff this season and rank only in the middle of the pack in ERA (4.00) in the AL. RHP Justin Verlander, whom they reacquired in August in a deal with the Mets, has thrown well for them in 10 starts. He was especially sharp on Monday vs. Seattle, when he fired eight innings of one-run ball.