You do realize that batting average is probably the poorest representation of the skills of any hitter right? Not to mention the far more important defensive value Martin brings.
Because allowing the batter's to hit your pitches as an intention... is kinda dumb. It's fairly proven that managing weak contact isn't exactly a repeatable skill
Do you know for a fact it's velo he's having issues with? I can't imagine there's a huge average velo difference between AA and AAA with all the junkballers kicking around AAA