That strength coach, Dave Campbell, is also Georgetown's defensive coordinator. He is impressed with Grubbs' strength, both physically and mentally.
"Grubby, he is probably one of the most mentally tough kids we've had here," Campbell told the Georgetown News-Graphic. "He can work himself to exhaustion."
Grubbs said he's only put on about 10-15 pounds in his two years at Georgetown, but that his strength has improved greatly.
He has turned his work ethic and improved strength into a probable starting spot this season at linebacker for the Tigers, who played in their fourth straight national championship game last year.
Grubbs is listed first on the depth chart at outside linebacker after playing defense sparingly his first two years. However, he said even that experience will pay dividends in the upcoming season.
"We'd get up on people a lot and I'd usually get to play in the end of the third quarter and the fourth quarter," Grubbs said. "It's going to help this year and next year because I've had all the game repetitions. It's a lot better than just getting reps in practice because you get to see the game speed."
Grubbs spent the last two seasons backing up Shan Housekeeper, the team's second-leading tackler last year. Grubbs said that stepping into a starting role shouldn't be any different.
"With all the game reps that I got, I feel pretty comfortable about going in," Grubbs said. "I'm just going to try to keep doing what I've been doing. I'm going to have to take a little bit more of a leadership role this year.
"I'm just going to go and work as hard as I can. I know what it takes to get a starting position. It's tough, but you just keep working hard. It can get kind of rough if you go two or three years without playing, but if you keep working hard you'll make it."
He has definite goals for the upcoming season. He knows that his time on the team will come in handy when he's dealing with the younger players the Tigers have on the roster.
"I'd like to be in the top tacklers on the team and help the team get to another national championship and be a better leader as an upperclassmen," Grubbs said. "We have a real young team this year and some of the newcomers and the sophomores, they haven't ever won a national championship."
Grubbs is used to championships. He won a state title in his senior season at Danville, and has a national championship ring with Georgetown, as well as a national finalist ring.
Grubbs said it takes teamwork, something that he's come to understand, to win titles.
"You have to get everybody on the same page to know what it takes," Grubbs said.