18. Aaron Sanchez
Aaron Sanchez of the Toronto Blue Jays has already turned 25, but because a player’s age for an MLB season is determined by his age on June 30, he makes the cut for this list. The right-hander’s age-24 season has not gone according to plan at all. Sanchez has spent most of the season on the disabled list dealing with blisters caused by throwing his curveball.
Sanchez won the AL ERA title last year at the age of 23 with a mark of 3.00 while going 15-2 to post the best winning percentage in baseball. The Jays have been extremely careful in managing his innings, and even sent him down to the minor leagues at one point last year to skip a few turns through the rotation. For all the concern over keeping his elbow and shoulder healthy by massaging innings, it is crazy to think that it is a blister that has limited Sanchez to only five starts in the first half of 2017.
When Toronto finally got around to deciding that Sanchez would be a starting pitcher in the big leagues, he did not disappoint. He throws a sinker that consistently touches the upper nineties and just pounds it in on hitters. Sanchez can locate his fastball all around the strike zone to hunt strikeouts or weak contact. Developing a secondary pitch, however, has been somewhat difficult for him, as evidenced by his struggles with the curve this season. Paired up with Marcus Stroman, the Blue Jays have two of the best sinker-ball starters in the league.