TORONTO - A Canadian mixed martial arts fighter's bid to join the Toronto police department has been derailed just days after his successful UFC debut.

Sean Pierson was due to start his police training this week.

But Toronto police say its provisional job offer has been withdrawn because of concerns over Pierson's former nickname -- Pimp Daddy -- and the time fighting might take away from his police work.

Police spokesman Mark Pugash says: "The fact that it was mixed martial arts was not relevant."

The 34-year-old Pierson won his UFC debut on the weekend by decision over Matt Riddle at UFC 124 in Montreal.

UFC president Dana White called it the fight of the night.