McNeil's dynamic development isn't too surprising considering his background. The talented Texan was a four-star recruit rated America's No. 6 free safety by FOX Sports NEXT when he signed with Tennessee out of Dallas' Wilmer-Hutchins High School last February. A Parade All-American, he played in the U.S. Army All-America Bowl.
Like most college freshmen, however, McNeil struggled with the learning curve in his early days on The Hill. After seeing no action in Tennessee's 2012 opener versus North Carolina State, he recorded a tackle each in Games 2, 3 and 4 against Georgia State, Florida and Akron, respectively, before exploding for 4 solos and an assist in Game 5 at Georgia.
Based on that breakout showing in Athens, McNeil supplanted junior Brent Brewer as the first-team strong safety this week. How McNeil performs in his first collegiate start against unbeaten and 19th-ranked Mississippi State remains to be seen.
"Well, we're going to see how ready he is," first-year safeties coach Josh Conklin said with a laugh. "I think he's ready to go. We've tried to get him as ready as we can. It's another week that he's approached it the right way. He's worked really hard at getting in extra in the mornings after meetings, trying to get more work in, watching film and studying."
Senior Prentiss Waggner, who has started at both cornerback and safety for the Vols, believes McNeil is going to do just fine in his starting debut.
"I think LaDarrell will be ready," Waggner said. "One thing about LaDarrell: LaDarrell is going to play full-speed. We've got to do a better job in the background of helping him out on every play. (Free safety) Byron Moore's going to take control on the back end and help LaDarrell with the things he doesn't know."
At 6-feet-1 and 195 pounds, McNeil has a nice blend of size and speed for the safety position. He showed excellent footwork in preseason camp and seemingly has the tools to be an All-SEC player someday. All he needs is experience.
"He's just got to get out there and go play his game," Conklin said. "He's a good football player; he's just got to let the game come to him and know he knows what's going on out there. B. Moore's going to be a big part of that, as well. We've tried to get Byron Moore to understand that he's got to be more vocal back there. He's got to communicate more, be a signal-caller back there and help that young guy out till he gets used to what's going on."
Except for the Georgia game, McNeil's action this fall has been very limited. As a result, he's likely to feel some nerves in the early stages of Saturday night's game.
"Once you get through those first two or three series, now you can kind of settle in because you understand what maybe they're going to attack you with and the adjustments that are going to happen," Conklin said. "Now he can get settled in. When we get past those first two to three series, I think he'll be OK."
McNeil's combination of size and speed is rare among freshmen. Those attributes would be meaningless, however, if not for his greatest asset.
"His instinctive football ability," Conklin said. "That has never changed. That's what he was in high school; that's what he is here. He gives us a little bit of extra punch to the point of attack in the middle of the field. He can run the alley, which I think sometimes we've lacked."
Blessed with size, speed and instincts, McNeil now must show he has the intangibles to be an SEC-caliber safety. The poise and preparation he exhibited upon learning he'd start this weekend suggest he has those intangibles.
"I think he kind of expected it," Conklin said. "It's who he is. It's his makeup. I think he's ready for the challenge."
Vol defensive coordinator Sal Sunseri talks about what McNeil brings to the table, the brightness of the freshman's future and more in this video:
See Conklin talk about his young starter in this footage: