As a reminder, "Countdown to UFC 137" debuts tonight on Spike TV.
The half-hour preview show, which airs at 11:30 p.m. ET/PT, focuses on
Saturday's UFC 137 event, a lineup that's undergone numerous changes prior to the live pay-per-view airing from Las Vegas' Mandalay Bay Events Center.
The welterweight main event features recent Strikeforce titleholder Nick Diaz vs. ex-UFC champ B.J. Penn.