For one, the 6-foot-4, 230-pound O'Brien is a bigger and better overall athlete. Remember, he rushed for 626 yards (5.69 per rush) as a high school senior.
It also helps O'Brien that he joined the Nebraska program in January 2016, meaning this will be his second go-round in spring ball. He knows the lay of the land. More important, he knows the Mike Riley/Danny Langsdorf offense well, as does Lee.
What struck me last spring, as I first watched O'Brien go through drills, was how smoothly he operated. Although he's 6-4 and 230, he makes the quarterback movements -- hand-offs, fake hand-offs, pass fakes, drop-backs, roll-outs, et al -- look easy.
"You could tell he's played the position for a long time," said Reilly, who noted another quality that's critical in this discussion. "He's very confident in the huddle and with calling plays, and getting everyone lined up. That surprised me, especially coming in as a true freshman. He stepped up right away and didn't back down."
Didn't back down. Keep those words in mind as the spring season progresses.
"I'd still give the edge to Tanner, for sure," Reilly said. "But it's definitely going to be a good competition because Patrick isn't going to shy away from anything."