Darlington, a true freshman, was filling in for All-Big 12 lineman Gabe Ikard, who suffered a concussion against Iowa State.
Stoops, speaking to the media at his weekly press conference, said Darlington was on the money with all of his snaps, but it was Darlington's blocking that impressed him most.
Darlington was named the team's player of the game following the Sooners' 42-34 win over the Bears.
Up next for OU is a 6 p.m. date at West Virginia on Saturday.
Here is a look at what else Stoops had to say on Monday: