HOUSTON -- The postseason is drawing near, and it is fair to say that Lance McCullers Jr. looks ready for the moment after he struck out a season-high 11 in the Astros' 5-2 win over the A’s on Thursday night at Minute Maid Park.

Houston’s magic number to clinch a playoff spot is down to one. It will be the sixth straight season that the Astros will play meaningful October baseball.

• A's, Astros honor legacy of Roberto Clemente

It is fair to assume that Justin Verlander, who is in the midst of an American League Cy Young-worthy kind of year and returns to the rotation on Friday, and Framber Valdez, who has delivered 24 consecutive quality starts, will head Houston's postseason starting staff. The other starting spots are up for grabs, but the safest bet for that third spot is 2017 playoff star McCullers.

McCullers delivered a performance worthy of locking a spot in the playoff starting rotation, as he allowed just two runs on two hits and four walks in six innings.

“He got stronger as the game went on,” manager Dusty Baker said. “His pitch count got to where we wanted it to and he was throwing the ball well. He’s doing real good.”

It has been a long road for McCullers in his recovery from a right forearm injury sustained in last year’s AL Division Series. The right-hander, now in his seventh season, has been solid in his return, including his two scoreless outings in August, and he continues to go back to his vintage form as the playoffs loom.

McCullers elevated his game in the series opener, keeping A’s hitters guessing as he generated 16 whiffs (swings and misses) while logging his most strikeouts since July 29, 2018. McCullers fell one shy of his career high in K’s, but what matters most to him is the way his pitches are getting to where he expected them to be at this point in his return.

“I think my stuff is a little more crisp,” McCullers said. “I remember saying that in mid-September, we will look up and my stuff will be at the place we hoped it would be. It is trending in that way. The last two starts are an indication that I’m feeling really good with basically all my stuff.”

McCullers did run into trouble throughout his start, facing issues in the first inning with two on and two outs. He escaped that jam with no runs allowed, but he faced bigger issues in the fourth inning with bases loaded.

McCullers showed no panic, even though Dermis Garcia's two-run single gave the A’s a 2-1 lead.

“That’s just a veteran pitcher,” manager Mark Kotsay said. “A guy who’s had success, knowing how to shut an inning down and know that the at-bats that he really has to really bear down on, he does.”

McCullers saved his best for last late as he touched 95 mph with his sinker in the fifth inning. He finished the night at 99 pitches (59 strikes).

“It’s the most [velocity] I had late into a game and a pitch count,” McCullers said. “It really felt like my best stuff was probably the fifth and sixth inning. It is good to see that and feel that when you get deep into the ballgame.”

Houston’s offense matched McCullers’ performance, using a three-run seventh inning (fueled by Aledmys Díaz’s two-run shot and Kyle Tucker’s RBI single) to pull away for good.

The Astros are 94-50 and the magic number to clinch their fifth AL West title in the past six seasons is at six. The most encouraging sign is that they have McCullers back on his "A" game, posting a 2.34 ERA in his past six starts.

“The fact that we can control our destiny and fate at this late part of the season is nice,” McCullers said. “I want to be there in late October and hopefully into November. I want to be a productive part of this clubhouse when the club needs me to.”