SAN DIEGO >> Whether they’re in the field or at the plate, the Houston Astros are finding it tough to summon their usual postseason proficiency so far in the AL Championship Series.

Almost as tough as José Altuve is finding it to throw to first base from shallow right field.

Altuve’s two throwing errors were the lowlight of Houston’s 4-2 loss to the Tampa Bay Rays in Game 2 today, with his first error prolonging the first inning and leading directly to Manuel Margot’s decisive three-run homer.

“We’re very surprised,” Astros manager Dusty Baker said. “That’s his first throwing error all year, and he hit two of them today.”

Altuve’s mistakes and another quiet day at the plate have put the defending AL champion Astros in a 2-0 series hole in less than 24 hours in San Diego.

Houston is facing an 0-2 series deficit for only the second time during its current run of four consecutive playoff appearances with two AL pennants. The Astros lost the first two games of last year’s World Series to Washington before winning three straight and infamously losing two more in the first Series featuring seven consecutive losses by the home teams.

“We were down 0-2 in the World Series last year with (ALCS Game 3 starter) José Urquidy and (ALCS Game 4 starter Zack) Greinke coming up next to pitch for us,” shortstop Carlos Correa said. “It’s not like we haven’t done it before. It’s not impossible.”

But if defense wins championships in baseball, Houston’s gloves are not ready for rings. The Astros have made three errors in two games, while the Rays have played sparkling defense all across the diamond.

“Their defense is winning ballgames for them right now,” Correa said.

That’s definitely not true for Houston, which led the majors with a .991 fielding percentage in the regular season, making just 20 errors in 60 games.

Altuve is the normally sure-handed second baseman on one of the majors’ top fielding teams, but the six-time All-Star bounced two throws to first while playing in a defensive shift in Game 2. The Astros didn’t make Altuve available to reporters after one of his roughest playoff games.

“He’s been the heartbeat of this team, the staple of this organization for so many years,” said Houston starter Lance McCullers Jr., who pitched seven outstanding innings. “I really wanted to pick him up there. I wish we were talking about something different. He’s a hell of a player, and he understands how much we support him. He just needs to come back tomorrow like he always has.”

Altuve made his first error with two outs in the first inning when he fielded Ji-Man Choi’s grounder in right field and lobbed a poor throw to first for Yuli Gurriel, who also failed to bail out his teammate by snagging the low, but catchable ball.

Margot homered off McCullers two pitches later, putting three unearned runs on the board for Tampa Bay. Altuve was visibly disappointed in the field, dropping into a crouch while Margot rounded the bags.

Altuve’s arm failed him again in the third inning after he fielded Brandon Lowe’s grounder in right, bouncing another throw to Gurriel at first. Gurriel failed to help out again, and Altuve turned around to face the outfield fence, disgusted with himself.

“You just hope he isn’t getting the yips, because invariably they come in bunches,” said Baker, who gave Altuve a hug in the dugout after the third inning. “Everything comes in bunches. I just told him to flush it. This guy has been awesome for us. You’ve got to flush it and move on, or else it multiplies. I’m sure he’ll do that.”

After the second error, Correa moved into the spot normally occupied by Altuve in the shift.

“We didn’t move them,” Baker said. “Carlos and José moved themselves. You know how close these guys are. Carlos really looks up to José in ultimate admiration. They did that themselves.”

Correa spoke about the move delicately, saying he “did that because I feel like I can play back, and with my arm I can cover a little more ground.”

But the Astros’ normally reliable double play combination has been vulnerable at Petco Park in a series requiring a higher level of play to beat the impressive Rays.

Correa made Houston’s only error in Game 1 on a grounder by Mike Brosseau in the fifth inning, although it didn’t lead to a run. Correa made just one error in 57 games during the regular season, and that error on Sept. 1 ended his team-record, 90-game errorless streak at shortstop.

Altuve’s first error put the Astros in a hole they never escaped, even with a superb start from McCullers. The veteran right-hander pitched four-hit ball with 11 strikeouts, but his only run support came from Correa’s sixth-inning homer — his fifth in seven games, matching his entire regular season total.

After getting nine hits and just one run in Game 1, the Astros ended their 13-inning scoreless streak with Correa’s homer. But they didn’t rally until the ninth inning of Game 2, when they got three straight singles and loaded the bases twice but scored only one run.

George Springer grounded up the middle into a defensive shift, resulting in a bases-loaded double play that cut the deficit to 4-2. Altuve and Michael Brantley walked to bring up Alex Bregman, whose history of postseason heroics includes a walk-off single in Game 5 of the 2017 World Series.

The magic wasn’t there this time: Bregman hit a 98-mph line drive to right-center, but Kevin Kiermaier caught it to end Houston’s hopes.

The Astros knew they had lost this one eight innings earlier, according to McCullers.

“I went up to (Altuve) and said, ‘I know you’re disappointed, but I should have picked you up there,’” McCullers said. “‘Just keep doing your thing, and we’ll try to hold them at three.’ Get some runs off Chuck (Morton). But it’s hard. We had some guys on base today, hit some balls hard. It’s tough.”