With two open rotation spots after the Miles Mikolas injury, Carlos Martinez, Kwang-hyun Kim, and Daniel Ponce de Leon have come on strong in Spring Training. The trio have impressed this spring, and they have provided stiff competition for each other. However, entering the Spring it appeared that the Cardinals would give Carlos Martinez every chance to return to the rotation while Kim has simply been so dominant and impressive that it would be difficult for the team not to put him in the rotation, especially considering his left-handedness. Even though Ponce de Leon has pitched well in the spring, it seems likely that he will be on the outside looking in once again. While this is unfortunate for Ponce de Leon, it is the best scenario for the Cardinals, as a rotation with Martinez and Kim, as well as Jack Flaherty, has the potential to be very good.
Since arriving from Korea, Kwang-hyun Kim has showcased his strong pitchability and some nasty movement. The southpaw has shown an ability to throw his fastball up to 95 mph while his curveball features plenty of movement and can be thrown as slow as 68 mph. Throughout Spring Training he has shown an ability to disrupt a hitter’s timing with this nearly 30 mph difference, and he demonstrated this again on Monday vs. the Twins when he blew a 95 mph fastball by a hitter right after throwing a nasty curveball. Additionally, he has fanned 11 batters and walked just 1 while allowing no runs in his 8 innings of action so far this spring. His ability to control his pitches and fool the hitter gives him the potential to vastly outperform his modest contract. It is still Spring Training though, so even though he is performing well now, there is no guarantee that he will be as dominant once the regular season starts. Despite this, he has looked impressive and this will likely lead to him entering the Cardinals rotation this year, especially since he is a southpaw.
While Kim appears to have one spot locked up, Carlos Martinez has been solid as well. This will likely lead to him earning one of the final two rotation spots, as the Cardinals will want to see if he can return to his 2015-2018 form in the rotation. Martinez used to be one of the better starting pitchers in baseball, and even if he cannot return to that level of excellence, he still appears to be effective in longer outings. The right-hander has allowed just two runs in 9 1⁄3 innings of work. His K/BB ratio of 7/5 leaves a lot to be desired, but he has shown this spring that he is still capable of starting games. For example, on March 5 he tossed five scoreless innings while fanning two and pitching efficiently.
Even though Ponce de Leon has pitched extremely well this spring (13 IP, 1ER, 12K), he will likely be relegated to bullpen duty or be relegated to the AAA rotation. However, this is a good problem for the Cardinals to have. Kim and Martinez are two high upside pitchers who could pitch very effectively with the Cardinals and form a solid trio with Jack Flaherty. Additionally, Ponce de Leon could become a weapon out of the bullpen as he has pitched well the last two seasons while splitting time between St Louis and Memphis. Then, if someone gets hurt or proves to be ineffective, he would be capable of filling a rotation spot and providing solid innings. Also, When Miles Mikolas returns from injury, he will re-enter the rotation and that will prevent the Cardinals with a difficult scenario. If both Kim and Martinez are pitching well, then it will be hard to choose who to remove when Mikolas is healthy. However, having such a surplus of MLB caliber starting pitching should help the Cardinals not miss a beat when someone inevitably gets hurt. Another possibility is that Dakota Hudson or Adam Wainwright could struggle as Hudson’s 4.93 FIP in 2019 suggests that regression could be on the way, and Waino’s age (38 years old) could prevent him from pitching adequately.
While it can be argued that Ponce de Leon deserves an extended run in the starting rotation, especially after his strong results in the last two seasons, the team is better off with Kim and Martinez. Much like the outfield, the potential for the rotation is very high; however, there are still some questions marks. Regardless, the Cardinals are in a good situation with the surplus of pitching, and they should be able to boast an above average rotation during the season, especially if Martinez returns to his 2015-2018 form and Kim continues to dominate opposing hitters.