Mir, a former UFC heavyweight champion looking to rebound from his UFC 111 loss to Shane Carwin, checked in at 252 pounds for the bout, while Cro Cop -- a winner of two straight -- tipped the scales at 227.
"I'm not taking him lightly by any means," Mir said shortly after weighing in. "It'll be a very short night for me if I do. I'm just going to go out there and try to take care of him quickly, make it a quick night."
Mir, who cut weight to make the 265-pound limit in his last two fights, abandoned his once-stated desire for more bulk and returned to the size he's fought most of his career, while Cro Cop was lighter than he's been in the recent past. He's been 235 and 234 in his last two fights, respectively.
All 22 fighters comfortably made weight for the event, which marks the organizational debut in Indiana.
Ryan Bader and Antonio Rogerio Nogueira both weighed in at 205 for their light-heavyweight co-main event fight.
The largest cheers of weigh-ins were reserved for hometown fighter Chris Lytle, a longtime UFC veteran who is still an active fireman in the Indiana fire department.
Main Card Results
Mirko "Cro Cop" Filipovic (227) vs. Frank Mir (252)
Ryan Bader (205) vs. Antonio Rogerio Nogueira (205)
Chris Lytle (171) vs. Matt Serra (170)
Evan Dunham (156) vs. Sean Sherk (155)
Melvin Guillard (155) vs. Jeremy Stephens (155)
Spike TV fights
C.B. Dollaway (186) vs. Joe Doerksen (186)
Joey Beltran (239) vs. Matt Mitrione (253)
Pat Audinwood (156) vs. Thiago Tavares (155)
Steve Lopez (156) vs. Waylon Lowe (154)
T.J. Grant (170) vs. Julio Paulino (170)
Mark Hunt (265) vs. Sean McCorkle (263)