I've watched him about 4 or 5 times playing for Bologna, and now I can give a better insight as for why his Stamina, TW, TS and long passing stats need to be reviewed.
First of all, he doesn't dribble often because he's aware that he's not particularly good on the ball. Most of the time, he goes on the ball for a few metres. Then he gives a short pass to a teammate in the centre and he immediately moves forward off the ball even before his teammate receives the ball. The idea is that the teammate makes a one-two, so Krejci gets the ball and he already got past the opposition off the ball, thanks to his good sprint. He does this very often for the whole match, then he gets in a comfortable position to put an accurate and fast cross. That's how he gives his contribution when attacking. In defensive terms, he also tends to hug the left flank and he's very helpful tracking back and giving defensive covering or pressing when required.
He keeps doing these all the match; he barely manages to reach byline for a cross or cut inside on or off the ball.
That said, his style of play is summarized in: intenstivity, speed, physical fitness and will to support his flank at any time.
His Stamina is definitely of a high yellow value (at least), Top Speed at 85-87 and Teamwork around 83-85. His Agility and DS could be lowered to high greens, though.
I know I mentioned Beausejour to describe Krejci's style of play, but now I think he's even more similar to José Pedro Fuenzalida, a footballer who also excels much more as a sprinter, dynamic supportive team-player than as a flamboyant winger.