New York Mets right-hander Noah Syndergaard.Jim McIsaac/Getty Images Felix Hernandez, RHP, Seattle Mariners
A year ago, Felix Hernandez would have been a no-brainer. The six-time All-Star and 2010 Cy Young Award winner slipped from his throne last season, however, posting his highest ERA (3.82) since 2007 and fewest innings pitched (153.1) since 2005. A solid spring hinted at a comeback, but it's worth wondering if the soon-to-be 31-year-old will ever be king again.
Noah Syndergaard, RHP, New York Mets
Noah Syndergaard will have a place on this list soon enough. He has the look of a true ace, he has the triple-digit stuff of a true ace and, at age 24, he's probably going to get even better. For now, though, with less than two full big league seasons under his belt, Thor's resume is simply too thin.
Masahiro Tanaka, RHP, New York Yankees
If you add his body of work in Japan's Nippon Professional Baseball to the impressive things he's done in pinstripes, Masahiro Tanaka is in. He had his best season with the Yankees in 2016, but he's still yet to crest the 200-inning threshold. At age 28, with his elbow problems less of a distraction, he may get there.
Jose Quintana, LHP, Chicago White Sox
When the Chicago White Sox shipped Chris Sale to Boston, fellow lefty Jose Quintana became the team's best pitcher. He's quietly logged four straight 200-plus inning seasons with ERAs of 3.51 or better. Still, this is his first chance to pitch as a legitimate No. 1 (unless and until he's dealt). Let's wait and see how he responds.