MESA, Ariz. — During the A’s FanFest at the end of last month, several A’s players and officials alluded to the fact that various teams had complained to Major League Baseball about the Astros stealing signs via technology but that no steps were taken after the complaint.

On Tuesday, asked by The Chronicle if the A’s had complained to the league, Oakland manager Bob Melvin said that they had.

“Yeah,” he said. “But I don’t know what else they could have done at that point.”

It took Oakland pitcher Mike Fiers’ public allegations, Melvin said, to spur the league to launch the investigation that led to sanctions and suspensions levied against the Astros.

General manager David Forst confirmed that Oakland’s front office filed an official complaint, before Fiers’ accusations, regarding Houston’s sign-stealing.

“MLB does a great job of monitoring these things, but it’s very difficult if a team calls in and complains about something, they can only do so much,” Melvin said. “It took a player and a player who was on that team to put it over the top. And I think MLB is handling it very well right now.”

The A’s weren’t alone in their complaints about Houston.

“Nobody’s happy about it, whether it’s an individual or a team, whether it’s the Yankees they’re playing in the postseason or if it’s us,” Melvin said during an interview session at Fitch Park. “I think everyone was kind of fed up with it. ... At some point, we have to move past it.”

Susan Slusser is a San Francisco Chronicle staff writer. Email: sslusser@sfchronicle.com Twitter: @susanslusser