SAN FRANCISCO — Long-time baseball writer Jon Heyman riled up A’s players and fans with a tweet that was critical of the Oakland Coliseum.

Said Heyman’s tweet: “A shame the a’s and giants have to play these games at the coliseum while ATandT sits empty. #shame”

A’s reliever Sean Doolittle wasted little time in responding via Twitter, writing: “I can see why you don’t like it. We have a strict No High Horse policy at O.Co.”

The A’s hosted the Giants on Monday and Tuesday, winning both games. The teams play at AT&T on Wednesday and Thursday.

When asked about Heyman’s comment, A’s manager Bob Melvin said he takes issue.

“If you come out and experience the atmosphere at our ballpark, maybe you wouldn’t say that,” Melvin said, “because it’s a pretty dynamic atmosphere, with those fans being very vocal. It’s unlike anywhere else.”

So, what’s it like playing in Oakland with the Giants as the opponent?

“It was like a big, 35,000 capacity bar,” Melvin said.

Heyman, who writes for cbssports.com, backtracked a tad after Doolittle’s tweet. However, Doolittle ramped up the rhetoric.

“Also, your Sistine Chapel that is AT&T Park forgot the bullpens when they built the stadium,” Doolittle tweeted.