Freshly termed-out state Sen. Mark Leno is lacing up his sneakers for a run to become San Francisco’s first openly gay mayor.

And in a move that is bound to rattle City Hall, Leno has signed up Mayor Ed Lee’s political team to help with his exploratory bid for the 2019 campaign.

“‘Are you going to run for mayor?’ is the question I am most often asked around town,” Leno said. “I want those curious to know that I am seriously thinking of doing so.”

If Leno stopped short of officially declaring that he’s in, it’s only to avoid violating campaign disclosure laws that require a candidate to file a declaration of intent to start raising money — he’s not ready to do that.

But make no mistake, his hiring of the political consulting outfit SCN Strategies — headed by Ace Smith, Sean Clegg and Dan Newman — is intended to stake an early claim in the race and send a loud message to a long list of other candidates being mentioned as potential contenders.

SCN, whose clients include Gov. Jerry Brown. Lt. Gov. Gavin Newsom and Oakland Mayor Libby Schaaf, used the same early-out-of-the-gate strategy with their client Kamala Harris when former Sen. Barbara Boxer announced she wouldn’t seek re-election.

The tactic helped Harris, who was state attorney general at the time, establish herself as Boxer’s heir apparent.

The consulting outfit deployed a similar out-early, out-big strategy for Newsom in his 2018 gubernatorial bid.

But the SCN alliance with Leno is especially notable — and possibly politically dicey — for another reason. SCN ran both of Lee’s campaigns, but the centrist mayor’s views aren’t always in line with Leno’s more progressive agenda.

This isn’t the first time Leno has eyed Room 200. He considered running in 2015 after being approached by labor, business and neighborhood leaders upset about the city’s direction under Lee.

But given Lee’s big campaign fund, his strong base of support among Chinese American voters and his decent if slipping poll numbers, Leno concluded it wasn’t the right time.

Now, however, “the pendulum is going to swing in the progressive direction,” said SCN’s Clegg. “And Leno is head and shoulders above the field.”

The firm’s polls on Leno show him with low negative numbers in addition to high favorables, Clegg said, making him “the ideal ranked-choice candidate.”

Leno has another reason for moving early. Board of Supervisors President London Breed and supervisors Mark Farrell, Jane Kim and Aaron Peskin are frequently mentioned as possible candidates, as are City Attorney Dennis Herrera, city Assessor-Recorder Carmen Chu and Assemblyman David Chiu.

In the meantime, with the race still off in the distance, the 65-year-old Leno is scouting for a new full-time day job to keep him busy — either in or outside of government.

Med alert: University of California regents were a bit taken aback by a surprise conference call informing them that UC President Janet Napolitano was hospitalized for complications from her treatment for cancer.

“It was even more surprising to hear that she had been undergoing treatment for months,” said one regent, who asked not to be named because of the sensitivity of the matter.

The call came from Monica Lozano, chairwoman of the board, who had been kept informed about Napolitano’s cancer treatment since she was diagnosed in August. Regents got the call Tuesday, shortly before UC went public with the news.

Lozano went out of her way to say Napolitano was doing well and would be quickly back to work, our source said.

Napolitano was treated for breast cancer in 2000 and underwent a mastectomy, but UC has not disclosed the nature of her current cancer. In its public statement, the university said Napolitano was expected to be released from the hospital in the next day or two.

Sure enough, on Friday, the 59-year-old former Arizona governor and Homeland Security chief was back in the office.

Still, if everything was going so well — and there was no cause for alarm — why the call?

“That’s what some of us were wondering as well,” the regent said.

Warriors win: News that the California Supreme Court had rejected a last-ditch effort to halt the Warriors’ Mission Bay arena got big cheers at the team’s groundbreaking the other day — and it turns out the opponents themselves may have been responsible for the timing.

Days before the gathering, lawyers for the antiarena Mission Bay Alliance petitioned the court for an emergency stay to block the construction. Not only did the court deny the injunction just hours before the groundbreaking, it also declined to take up the entire case — putting a swift end to any more legal challenges that might have hung over the project.

As for the celebration, there was no escaping the front-row presence of Giants President Larry Baer, who even got a special shout-out from Warriors President Rick Welts for all his support.

Baer and the Giants, of course, made no secret of their unhappiness with the first spot the Warriors picked for their arena, right up the waterfront from AT&T Park. And courtside appearances aside, the Giants remain apprehensive about having to compete with the Warriors in Mission Bay for city resources and parking spaces.

On the ground: Overheard by Mayor Ed Lee’s staffers on his trip to Washington, D.C., last week:

“It seems every duck hunter in America has descended on Capitol Hill.”

And, on the Mall, this conversation between two women:

First woman: “Do you think those Melania first lady buttons were made in America?”

Second woman: “I doubt it. The guy who is selling them was definitely not made in America.”

First woman: “Trump will fix that.”

San Francisco Chronicle columnists Phillip Matier and Andrew Ross appear Sundays, Mondays and Wednesdays. Matier can be seen on the KPIX TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call (415) 777-8815, or email matierandross@sfchronicle.com. Twitter: @matierandross