Thomas will start against right-handers and be out of the lineup against lefties going forward, Theo Mackie of the Arizona Republic reports.

EDGE Analysis

This is an alteration the Diamondbacks introduced over the last week, but it was uncertain how long it would last. Thomas is a prized prospect but is struggling with pitches on the outer half of the plate, and now he must contend with the suddenly hot Dominic Fletcher, an under-the-radar prospect who was called up to help fill in when Corbin Carroll injured his knee two weeks ago. Carroll is back and Fletcher is in the midst of a career-enhancing series against the Giants, going 8-for-12 with a double, a triple, two home runs and 11 RBI. Lourdes Gurriel typically starts against lefties, but his starts will now come at the expense of Thomas instead of Fletcher.