DeChambeau, 32, looked to have lifted himself to one shot off the lead on Friday – finishing seven under par with a four-under 66 – but was punished after being deemed to have trampled on long grass close to his ball on the fifth hole.
There had been some doubt about whether DeChambeau would continue playing at the tournament, but later on Friday he said the decision would “fire” him up for the weekend.
The two-time US Open champion, who is now three shots behind Australian overnight leader Lucas Herbert, tees off at 15:30 BST.
Darbon would not be drawn on whether DeChambeau had threatened on Friday night to pull out of the weekend.
“It’s fair to say there was some emotion around that and we will keep some of the aspects of that discussion private,” Darbon said.
He added: “There was some emotion but I empathise with that. Bryson has played a great round of golf, is in contention at a major championship, he wants to win the golf’s original major.
“We were focused on the ruling and making a fair assessment.”