Thorpe was demoted to Triple-A Rochester on Friday, Betsy Helfand of the St. Paul Pioneer Press reports.

Thorpe was moved to the temporarily inactive list Saturday, Brandon Warne of ZoneCoverage.com reports.

The Twins optioned Thorpe to Double-A Chattanooga on Wednesday.

Thorpe was added to the Twins' 40-man roster Monday, Brandon Warne of The Athletic Minnesota reports.

Thorpe gave up one run over four innings with three strikeouts and no walks Friday for Low-A Cedar Rapids. It was his first outing since August 2014.

Thorpe (elbow) likely won't ramp things up until spring training, Baseball America's Michael Lananna reports.

Thorpe (elbow) has begun a throwing program after missing a month with mono, Mike Berardino of the St. Paul Pioneer Press reports.

Thorpe has a torn UCL and needs Tommy John surgery, the Star Tribune's LaVelle Neal reports.

Thorpe, who is returning from a sprained UCL, came out of his most recent appearance with elbow pain, Mike Berardino of the St. Paul Pioneer Press reports.

Thorpe, coming off a sprained ulnar collateral ligament in his left (throwing) elbow, didn't pitch in winter ball and the Twins are hopeful an offseason of rest will correct the issue, the St. Paul Pioneer Press reports. "Right now we're expecting him to break (camp)," said Brad Steil, Twins director of minor league operations. "Depending on the throwing program and the point we get him back on the mound, we are hoping he'll break with the club."

Thorpe has been diagnosed with a sprained ulnar collateral ligament in his throwing elbow, Mike Berardino of the St. Paul Pioneer Press reports.

Thorpe, 18, has a 4.74 ERA and 44:20 K:BB ratio through 43.2 innings for Low-A Cedar Rapids.

Thorpe will begin the 2014 season at Low-A Cedar Rapids, the Minneapolis Star Tribune reports.