Oakland City Councilmember At-Large Rebecca Kaplan is doing nothing to douse rumors that she’s about to announce another run for mayor — possibly as early as Wednesday.

“I am considering it,” Kaplan told us late Friday, taking aim at what she sees as “Oakland’s rising problems” under incumbent Mayor Libby Schaaf — including “skyrocketing rates of homelessness and illegal dumping, which the current administration is failing to implement solutions for ...

“Also, Oakland continues to suffer from the worst air quality in the region,” said Kaplan, blaming Schaaf for cutting off the city’s “access to funding and solutions” when she recommended that Kaplan be replaced on the Bay Area Air Quality Management District board with Berkeley Mayor Jesse Arreguin.

Veteran East Bay political consultant Doug Linney, who ran Kaplan’s 2008 and 2016 campaigns for city council, said a friend texted him last week that Kaplan was about to announce her third run for mayor and, frankly, he was taken aback.

“I’m a bit disappointed but not surprised,” Linney said before Kaplan confirmed her interest. “I just think it’s a bad move for her.”

As he sees it, Donald Trump’s recent decision to take on Schaaf when she alerted the public to Immigration and Customs Enforcement sweeps has “made her a hero to a lot of people who may not have paid attention to what she was doing.

“Everyone understands it’s a hard office and a tough city to rule, and Libby has been giving her full attention and bringing a pretty considerable skill set to it,” Linney said. “So I think she gets lots of support — and someone has to come along and prove they can do a better job or else it’s a hopeless mission.”

Linney says he believes Kaplan has shown an ability “to think outside the box” and to produce “great policy initiatives,” but he also questions whether her go-it-alone approach to politics will allow her to build the coalitions needed to win a race in November.

Linney said he had urged Kaplan not to challenge Schaaf some time ago, but she had been evasive about her decision. He was not asked to join any potential campaign.

In November 2010, Kaplan placed third in ranked-choice voting for mayor, finishing behind Jean Quan and runner-up Don Perata.

In 2014, she finished second in a field of 15 candidates, but well behind Schaaf.

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