Zack Greinke’s abrupt regression is a problem for the Astros in more ways than one

Just a few weeks ago, only one time all year had Zack Greinke allowed five earned runs or more. Following yesterday’s start, he’s now allowed at least five earned in three consecutive starts. Sunday afternoon’s five-run outing against the Diamondbacks saw the crafty righty induce just two swinging strikes in his four innings of work. Three weeks ago, I wrote about how Greinke had been succeeding for much of the season despite being unable to miss bats, and wondered if it would eventually catch up to him. It appears that might be happening.

The Diamondbacks are one of baseball’s doormats — only the Orioles possess a worse record. And yet their lineup scored more runs off Greinke than the number of innings he pitched. At .227, Arizona’s hitters collectively have the fourth-lowest Expected Batting Average (xBA) in the big leagues, according to Statcast. Yesterday against Greinke, it was .415.

The elder statesman of the Astros starting rotation has given up five home runs combined over his past three starts. When the Diamondbacks’ Pavin Smith took him deep yesterday, it was the 29th home run Greinke had allowed this year, the most he’s ever surrendered in a single season.

Despite being in a funk, there hasn’t been any indication that the Astros would amend their rotation. Dusty Baker recently made it known how confident he is in his starting pitcher:

The Astros skipper’s seemingly blind faith in Greinke could prove to be rather problematic for the team. October is right around the corner, and with the club having alternatives to Greinke on a starting staff that will feature four of he, Lance McCullers Jr., Luis García, José Urquidy and Framber Valdez in the playoff rotation, a possible demotion shouldn’t be out of the question. But considering Baker’s steadfast belief in Greinke and his standing as the team’s most accomplished pitcher, such a notion probably isn’t feasible.

Getting teed up by the likes of the Diamondbacks and Rangers is already concerning, but Greinke’s struggles have come at an inopportune time with the playoffs slated to begin in two weeks. What’s particularly unfortunate is the potential cause of this downward spiral wasn’t of his own making.

On August 31, the 37-year-old veteran was placed on the COVID injured list and subsequently missed multiple starts due to testing positive for coronavirus. Although Greinke is fully vaccinated and said he did not experience any significant symptoms while in quarantine, it’s possible that the two-week absence has affected his performance, and rebuilding some lost arm strength may be necessary.

Going forward, it’s imperative for Greinke that he formulates a more effective approach when facing right-handed hitters. They’ve been his Achilles’ heel all season and have been feasting at the plate against him, as evidenced by a wOBA that’s north of .350. Righties are not necessarily getting on base a great deal versus Greinke, but 22 of the 29 home runs hit off him have come via right-handed bats.

These final regular season starts will be highly important for the six-time All-Star. Not just because the Astros need him to revert back to his old form, but because if he doesn’t, it seems unlikely that a change will be made, which could later cost the club in the postseason.