By the time he spoke with media after the game, he had already diagnosed his problem -- inconsistent lower-body mechanics.
"Me and [assistant pitching coach Rick Kranitz] were able to pinpoint that coming out of the game, kind of collect my thoughts a little bit and take a look at it," Eickhoff said. "It's a very easy fix. Just looking at video from last year, you can visibly see it."
Eickhoff was tagged with five earned runs in just 3 2/3 innings -- the shortest outing of his career.
The pitcher Eickhoff has been over his last three starts is not the one the Phillies are used to. In his first 45 career starts, Eickhoff allowed five-plus earned runs just four times. In his three starts since, he's done it twice while watching his ERA jump from 2.55 to 4.76.
While he chalked up his last two starts more to bad luck than any specific issue, that mechanical hitch Tuesday impeded his ability to hit his spots.
Fighting his lower half, Eickhoff walked more batters (three) than he struck out for the second time in his career.
"He had poor command, it boiled down to that," Phillies manager Pete Mackanin said.
It was an unusual sight to see the mentally strong righty workhorse both openly show frustration on the mound and leave a start so prematurely.
"I'm usually good about putting that behind me, putting that aside," Eickhoff said after he was unable to complete the sixth inning in his fourth straight start.
Prior to his current streak, he had never thrown fewer than six innings in any two consecutive starts.
The salt in the wound was that, unlike the vast majority of Eickhoff's young career, he received adequate run support early, but couldn't hold up his end of the bargain.
Since 2016, the Phillies have scored less than 2.5 runs of support per start behind Eickhoff, the lowest for any National League starter. Tuesday, his offense spotted him four runs in the first inning.
"I let these guys down," Eickhoff said. "It starts with me and that can't happen in that situation. It felt like I let them down."
Ben Harris is a reporter for MLB.com based in Philadelphia.