The beginning of the season was not necessarily good for the Phillies' pitching staff. It all began when the staff surrendered ten earned runs on Opening Day to the Texas Rangers. Through the months of March, April, and May, the Phillies pitching staff had a 4.65 ERA. The starting staff could not seem to pitch deep into games and the bullpen had some inconsistent pieces.
Phillies' bullpen success
The bullpen began to hit its stride before the rotation did. While some of the relivers still have inflated ERAs, they pitched well in April and May. For example, Gregory Soto has a 4.55 ERA on the season, but in April he had an ERA of 0.71. ERA is a tough stat to use for relief pitchers because of the lack of innings they accumulate on a month-to-month basis.
The continued dominance of left-handers José Alvarado and Gregory Soto, the resurgence of Craig Kimbrel, and the surprising contributions from pitchers like Andrew Vasquez and Jeff Hoffman have all factored into the Phillies' bullpen keeping offenses in check. The Phillies' relievers as a unit have the seventh highest K/9 rate in baseball on the season. The bullpen has shown that it can be dominant.
The Phillies' starting rotation has been rejuvenated
The Phillies' rotation has really turned things around since the opening of the season. Zack Wheeler has been the most consistent member of the starting staff; however, he did not pitch into the seventh inning until May 10th. Since then, Wheeler has gone at least six innings in all but two of his next eight starts. Wheeler's velocity has remained consistent since his May bounce-back.
Aaron Nola has gotten quite a bit of negative press this season. Nola has had his struggles but lately, has seemed to be getting back on track. Through March and April, Nola sported a 4.49 ERA. In May the right-hander's ERA was 4.93. Nola's first two months were inconsistent, and he struggled to maintain velocity as he went deeper into games. In June, however, Nola has a 3.46 ERA in four starts. In two of those starts Nola did not allow a run to score. Through 26 innings in the month, Nola has struck out 33 opposing hitters. Nola's numbers and improved velocity as he enters the later innings indicate that he may be turning his season around.
Taijuan Walker— similar to Nola— had a rough start to the season. May was a particularly difficult month for Walker as his ERA was a ghastly 6.11. Walker's first start in June was a rough outing in which he allowed three earned runs in four innings to the New York Mets. Since that start, however, Walker has allowed just two earned runs in 26 innings. In those 26 innings, Walker is averaging a strike out an inning.
Ranger Suárez missed the first month and a half of the season due to a forearm injury he sustained prior to the World Baseball Classic. Suárez missed all of spring training and only had three rehab starts to build up his arm strength. His early season struggles were perhaps to be expected. In his first 11 innings, Suárez allowed 12 earned runs. Since then, Suárez has returned to his old reliable form— and maybe has been a bit better. In the month of June, the left-hander has a 1.04 ERA, allowing just three earned runs in 26 innings.
Getting Walker and Suárez back on track has been massively important for the Phillies rotation. If Nola can get back into a rhythm, the top four in the rotation are a formidable group. The fifth spot in the rotation has been a weakness all season, but Cristopher Sanchez has had two solid starts since being recalled a couple weeks ago.
Per FanGraphs, the Phillies' pitching staff has a 3.90 FIP— a stat that takes into account the aspects of a game that the pitcher controls— which is fourth best in baseball this season. The Phillies' pitching staff has been limiting the number of walks which has helped contribute to their recent success. Over the last month, the Phillies have a walk rate of 2.53 BB/9 which is also fourth best in baseball over that span.
While the Phillies' offense has been largely inconsistent, the pitching staff has kept the club afloat for the month of June in which they have a 14-7 record. The staff will need to remain consistent and effective to keep the Phillies competitive until the offense can wake up consistently.