The Twins will send left-hander Pedro Hernandez down to Triple-A Rochester and call up reliever Caleb Thielbar, according to TwinsDaily.com.
The move may open the door for prospect Kyle Gibson to be called up for Friday's game in Detroit, Hernandez' next scheduled start.
Thielbar, a former St. Paul Saint, has a 1-1 record at Rochester in 17 appearances. In 26.1 innings pitched, he's given up 11 earned runs for a 3.76 ERA -- striking out 34 batters.
Hernandez, Fox Sports North points out, was acquired from the White Sox in the Francisco Liriano trade last year. He made his Twins debut this season and was 2-1 with a 5.85 ERA in eight games (six starts).
As for Thielbar, who is this guy? Here's a clip from the Red Wings YouTube channel: