Surprisingly enough, having to compete with his more celebrated classmate - for attention and carries - doesn't seem to bother Oku one bit.
"There's things that Bryce does better than I do and there's things I do better than Bryce," Oku said this week. "If you don't like competition you really shouldn't be here playing football. That's the whole purpose.
"Competition makes you get better as a player when you don't even know it."
Brown (6-0, 215) and Oku (5-10, 184) are different body types who bring different running styles to the tailback position. Brown is a power runner with surprising speed; Oku is the classic scatback with explosive quickness and cutting ability.
"Bryce is real speedy, I'm real speedy," Oku said. "I'm quick, and I feel like I have an advantage in vision. Bryce is more of a power runner. Sometimes I could probably lower a shoulder but you won't catch me doing that too much (laughs). He can do that all the time. He's like 215 and I'm like 184.... There's some things that everybody does better than somebody."
Although he's 30 pounds heavier, Brown actually has more straight-ahead speed than his fellow freshman tailback.
"He's probably faster," Oku conceded. "The dude can move, man. He can move for a 215 (pound) guy.... But I can change directions quicker than he can. I've got him there."
That comes in handy at the collegiate level. The ability to change directions in a flash helps a back avoid taking head-on hits ... something that happened twice to Bryce in the Vols' first preseason workout. Brown took brutal hits from linebackers Herman Lathers and Rico McCoy, causing him to fumble each time.
Watching those licks from nearby, Oku was a little unsettled.
"I think I did a prayer real quick," he recalled, crossing himself to underscore the point. "I thought 'Oh, my God.' But that's college football for you."
Following Lathers' bone-jarring hit on Brown, Oku was understandably nervous as he waited for his turn to face the hard-hitting Vol defense.
Closing his eyes as if in prayer, he said: "I was like 'Please don't let me get hurt. Please don't let me get hurt.' It's different than high school. You can't do all of these spin moves, juke left and right."
Oku noted that in high school he could reverse his field twice on a single run "and not get touched." Those days are gone.
"You can't do that here in the SEC," he said. "You cannot do that. You have to get the ball, make your one cut and go straight."
Asked if Lathers' hit on Brown essentially said, 'Welcome to college football,' Oku grinned and replied: "I guess you could say it was a welcoming party for both of us."
Oku performed exceptionally well in Saturday's scrimmage, UT's first of the preseason, rushing nine times for 38 yards with a 40-yard run nullified by penalty. He experienced some butterflies in his stomach the first time he lined up at tailback.
"Thank God, we ran a play-action first, so I got 'em out," he recalled. "We ran a play-action first, and I was like, 'Oh, my goodness gracious. Woo! Lined up back there and thinking about taking that first hit, I was relieved when it was a play-action. That got my butterflies out."
In addition to Brown, Oku is competing with two veteran tailbacks - senior Montario Hardesty and sophomore Tauren Poole. Asked what he must do to win playing time as a true freshman, Oku paused thoughtfully before responding:
"Basically, just doing everything right - technique, running the ball correctly, making one cut and not going side to side, things like that. Also working hard at the punt-return and kick-return game.
"Basically, just working hard at whatever you do to get in the game ... to separate yourself from everybody else."