This is the sort of stylistic clash that makes for a very interesting and potentially exciting fight. Alexander is a classic boxer who can take a decent punch. Soto Karass is a high-volume brawler with good ring savvy and some boxing skills.
Alexander was an amateur standout from a young age who won 300 bouts as a teenager and came within a whisker of making the 2004 Olympic team when he was just 17. As a professional, he's won world titles at 140 and 147 pounds.
In Alexander's native St. Louis, he's the kind of star who gets invited to throw out the first pitch at Cardinals games. His popularity with boxing fans nationally has lagged behind that somewhat.
Alexander lost his IBF welterweight belt to Shawn Porter last December in an excellent fight. His other loss came against Timothy Bradley in 2011, although he got a gift decision against Lucas Matthysse later that same year.
But he also handed Marcos Maidana a boxing lesson in 2012. When Alexander is fully on, he's among the top welterweights in the world.
Soto Karass is perhaps the most formidable gatekeeper in the division. He had big wins over Selcuk Aydin and Andre Berto in 2013 before losing by Round 9 TKO to Keith Thurman in December. If he can rebound to beat Alexander, he'll have to be viewed as a contender.