Yordano Ventura has yet to realize a lot of the promise surrounding his career and there is a new concern about his ability to harness that potential for the Kansas City Royals.

Ventura, who will turn 25 next month, has a 4.62 ERA, 1.568 WHIP and a Major League-leading 28 walks issued in 37 innings this season.

Among qualified starters, Ventura is the only one to have a higher walk percentage than strikeout percentage. His -1.2% K-BB% is more than two points lower than the second-worst -- Martin Perez at 1.0%. No pitcher had a negative K-BB% in 2015.