Griekspoor, who played with a bunch of tape on his abdomen, started his first fourth-round tie at a Grand Slam brightly and went up 3-0 before a total collapse saw the Dutchman lose nine of the next ten games.
During the press conference after the match, Griekspoor confirmed a sudden abdominal muscle injury sustained during the warm-up forced him to withdraw in the second set at a score of 6-4, 3-0. "As a result, I couldn't serve at full power and couldn't compete the way I wanted to.
"I just couldn't serve faster than 180 kilometres per hour, and that dropped to 150."
The 28-year-old Dutchman said he'd never had this injury before. "I felt it during the last few serves in the warm-up and had a scan done before the match. Nothing showed up on the scan, but that's probably because it was too soon after it happened."
Griekspoor felt he had a chance against Zverev, whom he beat at Indian Wells earlier this year and always puts up a good fight against.
"I tried. This is one of the most important matches of my life, on a beautiful court against an opponent I enjoy playing against. So I wanted to try, but I quickly realised it wasn't going to be my day."
It's doubtful whether Griekspoor will feature in his planned first tournament of the grass season, the Libema Open in the Dutch town of Rosmalen, which will take place next week.