The defensive tackles are also currently without a coach. Longtime position coach Jackie Shipp was fired last week, and coach Bob Stoops has yet to hire a replacement.
Peterson, Phillips and Wade have seen little or no action throughout their college careers; Phillips played some in reserve duty last season, and is considered a raw talent with a high ceiling.
Junior college transfer Quincy Russell, from Trinity Valley Community College in Texas, was supposed to enroll early and participate in spring football, but academics prevented him from doing so.
He's now expected to arrive in the summer, along with Oklahoma's three incoming freshman defensive tackles.