It was revealed in July that the two were planning a one-on-one, winner-take-all event, and while the original prize was set for $10 million, the purse is yet to be determined.
Given that the showdown is taking place in Sin City, betting odds have already been established, with Tiger coming in as the early favorite.
Mickelson originally joked about the idea of a match against Woods at The Players, where Tiger happily responded he'll play for "whatever makes him uncomfortable."
After being linked as rivals throughout their historic careers, Tiger and Phil have made amends over the years, participating in several practice rounds together this season. Both players are in the field for the WGC-Bridgestone Invitational this weekend, and should be teammates on the U.S. Ryder Cup squad in September before they square off in what will be one of the most highly anticipated events on the golf calendar.