B.J. Penn could be on the brink of a career rebirth at 145 pounds on Sunday night, when he meets Frankie Edgar in his featherweight debut.
Or, the 35-year-old former welterweight and lightweight champion could be on the brink of retirement.
If Penn loses to Edgar in the main event of The Ultimate Fighter 19 Finale at the Mandalay Bay Events Center, his boss is going to suggest he walk away.
"This is B.J. Penn's last fight possibly," UFC president Dana White said Tuesday on FOX Sports 1. "If he wins, we'll see what he does from there, but if he loses, I will actually push for him to retire."
Penn, though jumping to another weight class, is still 1-4-1 in his past six fights. He hasn't won since knocking out Matt Hughes at UFC 123 in 2010.
"It could be possibly watching Michael Jordan playing his last basketball game," White said. "It could be Tiger Woods' last golf game."