“If there was an adverse development with respect to that referendum, that would be a significant development,” Manfred said Friday, before Game 1 of the World Series. “That’s all I can say about that.”

A Nevada teachers’ union has launched a petition to qualify the referendum for a public vote, arguing that voters should have a say in whether taxpayer funding should be spent on a ballpark. The A’s have joined a lawsuit asking a court to throw out the petition based on its technical defects. A hearing is set Nov. 6, according to the teachers’ union.

In June, the Nevada legislature approved — and Gov. Joe Lombardo signed into law — a bill that would provide $380 million toward the $1.5-billion stadium the A’s and owner John Fisher plan to build in Las Vegas. Major league owners are expected next month to approve the proposed relocation — the first in the league since 2005 — and the A’s hope to open the new stadium in 2028.

It is unclear whether the A’s would proceed with the move without the promised public funding. During testimony before the Nevada legislature, Las Vegas Convention and Visitors Authority President Steve Hill said he believed the A’s would not return to Oakland if the Las Vegas deal fell apart but would instead look to move elsewhere. Portland and Salt Lake City would be among the likely suitors.

It also is unclear where the A’s would play between 2024, the last year of their lease at the Oakland Coliseum, and 2028. Tony Clark, the executive director of the Major League Baseball Players Assn., said Friday the union has had “ongoing dialogue” with the league about where the A’s would play in the interim but said nothing has been decided.

The union has no say in whether the A’s move, but Clark said the league needs to finalize a decision and its impacts on players “sooner rather than later.” In speaking with reporters Friday, Clark also expressed the same curiosity about the potential move that many Oakland fans have expressed.

“I do find it interesting,” Clark said, “that, amid the conversation and dialogue around finances, rather than staying in the sixth-largest market, they’re moving to a market that may have them in a perpetual cycle of receiving revenue sharing.”