That didn’t last long.

One day removed from a three-hit game in which he blasted a home run and a triple, Jason Bay was moved back into the Mets’ cleanup spot — but his brief success didn’t continue.

“I expected to play and if I was batting ninth, I [couldn’t] care less,” said Bay, who said he wasn’t aware he was hitting in the cleanup spot last night until reporters told him shortly before batting practice.

“It doesn’t change anything.”

BOX SCORE

It didn’t do him much good, as Bay reverted to the form that has been all too familiar this season, going 0-for-5 with three strikeouts in last night’s 3-2 win over the A’s at Citi Field.

Bay grounded out to short with the potential winning run on second in the 10th.

Manager Terry Collins had sounded hesitant about moving him back up in the lineup, but the combination of the rest of the lineup not producing, as well as a lefty on the mound last night, forced his hand.

“We gotta have that guy that can really protect Carlos [Beltran],” Collins said of the right fielder, who has been hitting in front of Daniel Murphy lately. “And Jason gives us the best option.”

And from what Collins saw on Tuesday, he’s optimistic Bay is regaining his form.

“At least his bat was out in front,” Collins said. “He was letting the ball get too deep on him saw. He had good bat speed and I thought, ‘Maybe it’s coming.’ ”

*

David Wright took grounders on his knees for a second straight day before last night’s game. He is scheduled to have a CT scan on the stress fracture of his lower back today.

The results will help determine when the third baseman can return to baseball activities.

*

Justin Turner made another throwing error at filling in for Wright at third last night, and Collins remains concerned about Turner’s bruised thumb.

“It just won’t go away and I know it’s bothering him,” Collins said. “I’ll try to get him a day [off] here or there, but right now we need him out there.”

*

Collins talked with Dillon Gee after the right-hander lost his control in Tuesday’s loss, when he walked six batters in four innings.

“I asked him why he didn’t throw his curveball and he said he couldn’t locate his fastball, so why throw a curveball?” Collins said. “But if you’re gonna be ball one, why not give them something else to look at?”