The Washington wideout pulled up after the run and told NFL Network's Kimberly Jones his calf muscles were bothering him and that he wouldn't do any more drills, including a second attempt at the 40-yard dash.
"I felt good," Ross told NFL Network's Ike Taylor and Maurice Jones-Drew on NFL Network after his run. "I got tight at the end but it felt good coming out so I knew it was probably going to be pretty quick."
Ross went on to say he was grateful for the chance to show his speed at the combine.
"I'm just thankful beyond measure, blessed and just really happy to be in this situation," Ross told NFL Network's Michael Irvin about breaking the record, "because two years ago, I was sitting on the couch for the whole season, torn ACL, and now to be in this position, I'm really thankful."
When asked if he was disappointed that he didn't win the island that Adidas promised to the fastest 40-yard time wearing their cleats, Ross replied, "I really can't swim that well. And I don't have a boat, so you know, I had to run in Nikes."
Ross didn't make any bold predictions about breaking Johnson's record during his media interview Friday, but he did say he expected to run a sub-4.3 clocking.
Although Ross didn't have his breakout season at UW until 2016, his fourth year at the school, his reputation for blazing speed preceded that. He was named one of the fastest players in the nation by College Football 24/7 last summer after being clocked at 4.25 at the Husky Combine about a year ago.
Ross caught 81 passes for 1,150 yards and 17 touchdowns for the Pac-12 champion Huskies last year, and is one of three receivers frequently projected as potential first-round picks in the draft, along with Western Michigan's Corey Davis and Clemson's Mike Williams.