SAN DIEGO (CNS) - Acting Mayor Todd Gloria and former Councilman Carl  DeMaio are both expected to announce today whether they will seek to replace  Bob Filner, who resigned in disgrace after nine months as the city's chief  executive, while a county supervisor ruled out a mayoral run.

If DeMaio enters the race, it will mark the second attempt for the 38- year-old Republican, who narrowly lost to Filner in a runoff last November.  Gloria, a 35-year-old Democrat and the City Council president, would be making  his first run for mayor.

A run for mayor by Gloria and DeMaio would pit two prominent and openly  gay politicians against each other in the race to lead the nation's eighth  largest city.

Meanwhile, Supervisor Ron Roberts, who has run for mayor unsuccessfully  in the past, announced he would not seek the post.

``I made this decision after much discussion with my family and close  supporters,'' Roberts said. ``I will be forever grateful for their  confidence.''

The city of San Diego race will attract candidates who understand the  issues at City Hall, and the county still has some unfinished business, he  said.

Councilman Kevin Faulconer said he will announce his decision Wednesday  in a news conference on HarborIsland.

DeMaio and Gloria both planned to reveal their decisions today -- the  first regular working day for Gloria as acting mayor since Filner stepped down  amid allegations of various degrees of sexual harassment by 19 women. Gloria  assumed office when Filner's resignation became official at 5 p.m. Friday.

``I'm ready, I'm anxious to get to work,'' Gloria said. ``I have, like  every other San Diegans, been frustrated by what's not been getting done the  last number of months, and I'm really excited by the opportunity to actually  start doing that work again.''

He said one of his first actions would be to order a top-down review of  city departments to make sure city policies are being followed. He also plans  to talk to members of the mayor's staff and decide who he wants to keep.

Chief of Staff Lee Burdick, Assistant Chief Operating Officer Nelson  Hernandez, Council Liaison Francisco Estrada and Director of Community Outreach  Linda Perine left their posts on Friday.

Gloria will lead the city with limited powers until a new mayor is  seated. A special election, which could cost around $6 million, is set for Nov.  19.

Through Friday, 15 people have declared their intention to run. Among  the best known is former Assemblyman Nathan Fletcher, who finished a close  third in the June 2012 mayoral primary behind Filner and DeMaio.

Fletcher, an Independent who left the Republican Party after it endorsed  DeMaio last year, corralled the first endorsements in the race to replace  Filner. On Thursday, he announced endorsements from the unions that represent  the city's white collar workers and firefighters.

Since leaving the political arena, he has worked as an executive for  Qualcomm.

Upon narrowly losing to Filner in November, DeMaio set his sights on  Congress, saying he would challenge Rep. Scott Peters, D-San Diego, next year.  About 10,000 votes separated Filner from DeMaio out of more than 320,000 votes  cast.