I read this story in Omni in 1988, but I have no idea when it was published. The story was called "The Fighter", if I recall correctly, and the main character was named Teichart or Teichert Bohannon and his girlfriend was named Ricky Fandango. If anyone remembers this story and can tell me who wrote it or where I can find it, I would be eternally grateful.
From what I recall of the plot, the protagonist was some sort of gladiator who fought aliens in a future arena.