From Chronicle Staff Writer Susan Slusser in Anaheim

As The Chronicle reported first on Twitter this morning, the A’s decided against filing an official protest over last night’s ninth-inning obstruction call on first baseman Brandon Moss.

Assistant general manager David Forst told me that he, general manager Billy Beane and manager Bob Melvin spoke this morning, “and we ultimately agreed that it was a judgment call, as (crew chief) Gerry Davis said last night.”

The decision not to file an official protest does not indicate that the A’s believe the call made by home-plate umpire Greg Gibson was correct, however – simply that the play is not one that is eligible for an official protest.

“They applied the rule as written, which is that they thought Moss was in the baseline or impeding the runner’s progress – and that’s a judgment,” Forst said.

With no outs in the ninth last night, A’s reliever Dan Otero fielded a high chopper by Erick Aybar near the first-base line and banged into Moss as Otero was grabbing the ball. Otero then collided with Aybar, who appeared to veer inside the baseline toward Otero. Obstruction – always the call, not interference, when a fielder is deemed to have impeded a runner – was called on Moss.

“Obviously, I’m confused by it,” Moss said last night. “Dan actually ran into me, not Aybar. Then when Dan caught the ball, Aybar veered in, I know he veered inside the line. There is video to prove it.”

Otero said there was no other place for him to go to get the ball, and he thought he had the ball before Aybar ran into him.

Angels manager Mike Scioscia said last night, referring to Moss’ position, that Aybar “had nowhere to go. The fielder has the right to get the ball but he doesn’t have the right to block the runner’s path.”

Melvin’s response to that was that Aybar actually committed interferece: “They said he has to have a clear lane to the base – and one, he’s way out of the baseline, and two, he tried to make contact with the fielder.”

The play is not one that is reviewable on replay.

The A’s lost 4-3 in the 10th inning and they are two games behind the Angels in the AL West. There are three more games in this series at Anaheim, and more drama is likely.