Diaz is starting at first base and batting leadoff in Tuesday's AL Wild Card Series opener against the Rangers.
Diaz started just one of the Rays' final five regular-season contests while dealing with a right hamstring issue, but his availability for the AL Wild Card Series never seemed to be in much doubt. The American League batting champ is just 3-for-16 in his career versus Rangers starter Jordan Montgomery, although he has drawn five walks and hasn't struck out.