Don't worry, it's not as bad as it sounds.
The UCL, also known as the Tommy John ligament, can require a year-long rehab process should it tear.
Instead, since the injury was caught early, the Star Tribune's Lavelle E. Neal III says that Sano will rest for five weeks, and begin a rehab program after that, while he expected to be ready for spring training.
Sano hasn't played in two weeks, and played just two games before injuring the elbow.
Sano is widely considered a top five minor league prospect, and ranks No. 3 on MLB.com's list. He hit 35 home runs between Class A Fort Myers and Class AA New Britain last year.
An offseason lost for Sano, with hope that he comes back rested and ready to push for a major league roster spot with the Twins.