Hansen was transferred from Double-A Birmingham to High-A Kannapolis, Daryl Van Schouwen of the Chicago Sun-Times reports.
Hansen put up promising numbers in 2017, when he led the minors in strikeouts, but developed soreness in his right forearm during spring training this year and hasn't been right since. He didn't make his first start until June and is 0-4 with a 6.56 ERA and 10.7 BB/9 over 35.2 innings.