On a positive note, it wasn't the ACL, which recently sidelined UFC lightweight Joe Lauzon for at least a full year.
Bader improved his spotless record to 10-0 at UFC Fight Night 18 on April 1, but knew he would have to seek further medical attention on his knee.
"It was in the first [round], one of the first takedowns, I was passing from halfguard trying to pass to side control and I heard my knee pop, which isn't really a big deal because they pop every once in a while but I stood back up and I felt it was really, really loose," Bader told Steve Cofield of Yahoo! Sports after the fight.
Bader controlled the fight with his wrestling against American Top Team's Carmelo Marrero and won unanimously on the scorecards.