The former two-division champion will face Rory MacDonald in a highly anticipated welterweight showdown.
White believes it's all or nothing for Penn, who initially retired a little over a year ago. The fight against MacDonald is a chance for Penn to prove his relevance in the sport. A win would open the doors for a plethora of intriguing match-ups, but a loss would be devastating.
White recently spoke with MMAFighting's Ariel Helwani about Penn's UFC future, if he loses to MacDonald:
"He probably will [retire]. He hasn't said anything about that to me, but yeah, he's taken a year off and reflecting about things."
Penn announced his retirement in October 2011 after losing a lopsided unanimous decision to Nick Diaz. It was clearly a heartbreaking loss that pushed him into premature retirement talk.
Several months later, Penn was back in the fold, and MacDonald was named as his comeback opponent.
MacDonald, a protégé of UFC welterweight champ Georges St-Pierre, has been hailed as the sport's future, while Penn is constantly being referred to in the past tense.
During the media conference call for UFC on Fox 5, Penn admitted to being upset that his name was no longer mentioned in the all-time great category with St-Pierre and Anderson Silva. The mere thought of people viewing him as irrelevant has lit a fire under him that won't be ignored.
White believes fans could see the best BJ Penn ever. It only takes one look at Penn's physique to see the amount of hard work he put into preparing for this fight.
While MacDonald is a clear favorite, White wouldn't be shocked if Penn returns to form and stuns the young Canadian:
"You can see the difference in BJ Penn. First of all, he called Rory MacDonald out. He called him out, then he shows up in great shape, seems physically, mentally and emotionally ready for this fight...If [BJ] beats Rory on Saturday, wow, a lot of possibilities."