OK, it's Nutter. So, who's next?

It's official: The 2015 mayoral race kicks off today.

City Council primaries have concluded and Mayor Nutter is guaranteed a second term, so we can now turn our attention to the politicians jockeying for the mayor's office in four years.

Here is our best guesses on the likely candidates:

* City Controller Alan Butkovitz is seriously considering taking a whack at the office. His audits examining the administration are expected to increase within the coming months, but he still has to be reelected in two years to his current job before he can focus on the mayoral race.

Butkovitz told the Daily News in March that he couldn't yet declare anything but was considering the possibilities.

* At-large Councilman Bill Green, son of a former mayor, admits that he plans to attempt to follow in his father's footsteps.

Since taking a seat as an at-large Council member four years ago, Green has often butted heads with Mayor Nutter, criticizing his budgeting and tax policies.

* State Sen. Anthony Williams toyed with the idea of a mayoral run this year and appears to be a likely candidate for 2015. Williams' late father, the popular state Sen. Hardy Williams, was the city's first serious black mayoral candidate, in 1971. Unlike the rest of the mayoral hopefuls, the city's campaign-finance limits could pose a challenge to Williams, who would be new to the city's rules.

* District Attorney Seth Williams said that folks have constantly asked him whether he would consider running in 2015, but as of now he said that his sights are set on his 2013 re-election bid.

* At-large Councilman Jim Kenney has served five terms as councilman and has worked with three mayors in his 20 years at City Hall. Now, rumor has it he may be hoping to exchange his Council office for the mayoral suite on the second floor. Kenney was up for re-election and declined to comment.