Stoops said if doctors just find loose cartilage and repair it, Gresham could return this season. However, if a more extensive operation is needed, Gresham would likely miss the entire season.
The Sooners coach said magnetic resonance imaging tests don't show damage and the arthroscopic procedure "will be able to tell us what is making his knee lock."
Gresham, who caught 66 passes for 950 yards and 14 touchdowns last season, was hurt in practice last week before the Sooners' season-opening loss to BYU that dropped them from third to 14th in this week's national coaches poll.
Celebrity Families of 2014 [PHOTOS]