"You know, he's like the missing piece to our puzzle," Walker said about his teammate who has been reinstated from an indefinite suspension. "And so now we got him back, we're complete."
Complete with a trio of seniors in the middle of that defensive line, including McGee and Walker and also Jamarkus McFarland.
The latter two have anchored an interior defensive line unit that has more-than-shouldered the load that many thought it would coming into the season.
They've plugged the gaps and in the process anchored OU to the seventh-ranked rushing defense per Football Outsiders S&P with a 156.0 efficiency.
Not only that, but the two have been disruptive in the backfield for a combined five tackles for loss--McFarland has four of those--and two sacks.
McFarland's two sacks actually puts him a half sack off the team lead.
There's no question, though, despite their production, having another key cog to help them out in the middle will be crucial.
"Well obviously it lends us immediate depth," said defensive ends coach Bobby Jack Wright. "Good player coming back. And then with the guys that have been there kinda holding it down, it gives them an opportunity to get a little bit of a blow with the rotation, having Stacy involved there. So, we know we've got good guys there already and now with a former starter coming in there, certainly that's gonna--it adds depth and it adds quality of play.
"So, it gives us quite a bit on the inside, which again a guy that is a bigger body, can be more physical and we need that physicality in this type of game coming up this week. It's a big plus for those guys."
But it's also a big plus for Wright's unit.
Defensive end David King can now be just that, a full-time defensive end should the Sooners want to use him that way.
No longer will he be forced to move inside to work some snaps as a veteran presence.
And no longer will McFarland and Walker have to see 75 to 80 snaps per game without the depth behind them.
Effectively, it adds depth to the entire defensive line.
"I mean it does a lot," said defensive end R.J. Washington. "Stacy's a big, physical guy, strong guy. You know, he's a senior, so it's always good to see somebody in my class coming back."
Then, there were those words again.
"I feel like it might just be a missing piece," Washington said. "Mentally it helps because you know if somebody's tired, somebody needs to come out, we'll have a better rotation of guys in there. So, it's fresh and we all speed up because we got more people to rotate."
As for how they expect he'll play Saturday, well, suffice it to say they think he'll come out with the same energy as he had last season before his indefinite suspension during fall camp.
"Oh, I don't have no questions about it," McFarland said. "I feel like the same thing with Casey [Walker]. When those guys come back, they're not gonna miss a beat. We're gonna ride together."
Said Walker: "It's good. You know, I'm excited; I'm excited for him. You know, it's one of those things that it's like, ‘Shoot man. Long time coming. We gotta leave out with a bang together. We came in together and we're gonna leave together.' So, him coming back I'm excited."
So is everyone in Sooner Nation.
Maybe, for a defense that has already been much improved and at times even dominant under new coordinator Mike Stoops, the puzzle is now complete.