Minnesota has several internal rotation candidates, though. Here's a look at the starting pitchers, outside of Santana, currently on the 40-man roster:
RHP Kyle Gibson
It's telling that Gibson was Minnesota's second-best starter despite posting a 5.07 ERA in 25 starts. The sinkerballer couldn't build on his strong 2015 season, during which he had a 3.84 ERA, and dealt with back issues that limited his effectiveness. This will be a big season for the 29-year-old, who has struggled to put hitters away with his secondary pitches.
RHP Phil Hughes
After a down year in 2015, Hughes came into Spring Training in better shape in '16, but he dealt with thoracic outlet syndrome that led to season-ending surgery in July.