Diaz is a flamethrower that has the look of a late inning reliever. The issues come into play with lacking command at times and higher hit totals than desired. In three big league seasons, Diaz has a WHIP of nearly 1.30, which is higher than desired for a back end reliever, but the strikeout numbers are there as well with just south of 10 K/9. Diaz is also 32-years-old, which puts him on the back end of his career for a pitcher that relies on being a hard thrower. Diaz has a fastball that has seen triple figures at the big league level. Diaz also works in a devastating slider when he gets it across for strikes. There are questions about Diaz, but the velocity has never been one of them.