Thompson earned his first major-league call-up Saturday, Meghan Montemurro of the Chicago Tribune reports.
Thompson has yet to pitch above Double-A and has made just three appearances over the last two years due to injury and last year's canceled minor-league season. In 158.2 career minor-league innings, he owns a 3.46 ERA and 1.09 WHIP, striking out 23.4 percent of opposing batters while walking 6.0 percent. Kyle Ryan was optioned in a corresponding move.