Thornton (0-2) gave up four runs on six hits with three walks while striking out three through 4.2 innings in a loss to the Twins on Wednesday.
Thornton allowed nine baserunners and surrendered four runs to get the loss. After two solid starts with a combined 15 strikeouts to start the year, the 25-year-old has only struck out six in his last two outings. The right-hander has a 0-2 record with a 5.40 ERA through four starts this season. Thornton gets his next start Tuesday against the Giants.