Weird, random match-up. On the Iglesias vs. Ivanov undercard at Casino de Montréal on November seventh. I remember when the Argentinian was a ranked welterweight contender, a dozen years ago. Barely been on my radar for the last decade, and not at all for the last half-decade. Apparently he took a recent Icarus flight as high as super middle - and lost to a Russian novice, so he's retreating at least as far back as middleweight. Butler has hometown advantage and youth on his side, but is himself coming off a stoppage loss - his fifth, the Canadian being something of a knockout-or-be-knocked-out gunslinger. He will also have four inches of height and 8½" of reach on Chaves.
While I'd love nothing more than to see Diego pull off the upset, he has no business at 160, and he'll most likely get the Steve Rolls treatment.
I had to check it was the same Diego Chavez I knew, can't believe he is still going. Anyway given in his last fight he lost to a 4-0 neophyte I don't see him beating Butler, but I would be happy if he did.