HOUSTON -- The Astros are headed to their sixth straight postseason, but before the playoffs come around, they need to answer lingering questions, such as: Who will occupy that No. 4 spot in the rotation? José Urquidy seems to be the clear choice, but questions may arise after his tough outing in the Astros’ 8-5 loss to the A’s.

Here is where the Astros stand:

• Games remaining: 16
• Standings update: 14-game lead over the Mariners in AL West
• Magic number to clinch the AL West: Three
• Magic number to clinch the AL's No. 1 seed: Nine

One thing that is certain is the pitching staff -- which leads the AL in ERA (2.95), strikeouts (1,352) and opponents’ average (.212) -- will be crucial to the Astros’ success in October.

Assuming Justin Verlander, Framber Valdez and Lance McCullers Jr. will head the rotation, it leaves the group of Urquidy, Luis Garcia, Cristian Javier and Astros top prospect Hunter Brown as candidates for the fourth starting role. Urquidy, who was coming off a rough start against the Angels, did not help his case on Saturday, allowing six runs on seven hits in six innings.

“[Urquidy] is getting ahead of hitters but not putting them away,” Astros manager Dusty Baker said. “He didn’t have very good command of his breaking ball, and the changeup was a little hard.”

Urquidy was shaky from the get-go on Saturday, as he yielded three straight singles to open the game. He escaped with minimal damage, allowing just one run, but he wasn’t quite able to settle into a groove. A three-run fifth inning, in which Seth Brown launched a towering 432-foot homer, proved decisive.

It marked the second straight outing for Urquidy in which he allowed six earned runs and the first time he was tagged for back-to-back losses in his career. The righty’s uncharacteristic struggles come down to two factors: bad location and an ineffective changeup.

“I am leaving pitches down the middle,” Urquidy said. “I was throwing off-speed [pitches] very flat, and the hitters have been taking advantage of it. The changeup has been a little too fast and straight, too.”

Now the question remains: Who is going to be the No. 4 starter for the Astros in the postseason? Baker laid out the criteria last week, when he stated that he will look at the whole body of work, rather than just the numbers.

That may not be favorable for Brown, who has impressed since he was called up in September, but only has two big league starts under his belt.

Javier is a strong candidate, as he can be a strikeout machine (11.8 strikeouts per nine innings), but he can struggle to find the strike zone at times and has the most bullpen experience of the four.

Then there’s Garcia, who was in the bullpen on Saturday due to Phil Maton and Ryne Stanek being unavailable. The 25-year-old is 12-8 with a 4.04 ERA in 25 starts, making him a candidate to rival Urquidy.

Despite his recent struggles, Urquidy is in the midst of the best season of his four-year career, as he has already reached career highs in wins (13), starts (27), innings pitched (157) and strikeouts (127). He also has extensive playoff experience, posting a 4.05 ERA in 33 1/3 career postseason innings, including three wins in the World Series.

Baker will continue to evaluate the pitchers in the final weeks of the regular season, but one thing to note: He has not lost faith in Urquidy.

“Guys go through these ups and downs,” Baker said. “I have full confidence in Urquidy. You don’t lose confidence in a guy because of a couple of rough outings.”