But that isn't the only key Greer holds. He also holds a key ring featuring the Florida Gator logo as a constant reminder of the importance of the Vol-Gator game.
Pulling the keys from his pocket, he revealed the keychain to a group of onlookers earlier this week.
''I found this on the way to the guidance office last year before two-a-days,'' he said. ''Every day since, I see this and know that this is THE game ... not only for me, but all my teammates.''
Because he uses his keys every day, Greer says the Gator game is never far from his thoughts.
''This,'' he said, ''is a constant reminder of what it means to play at Tennessee and in the SEC. This is it.''