By Sam Frost Phil Mickelson believes the major championships will have no choice but to cave under pressure from LIV Golf as the breakaway tour continues to add top players to its roster. LIV players have no means of qualifying for the majors through their performances on the Saudi Arabia-backed tour, with the competition not sanctioned by the Official World Golf Ranking. LIV players have tumbled down the rankings as a result, meaning the likes of Mickelson, Dustin Johnson and Bryson DeChambeau have had to rely on previous successes at the majors to book a place in the biggest tournaments. Whi…