On Monday, tennis stars like World No. 1s Jannik Sinner and Aryna Sabalenka released a joint statement criticizing the prize money pool at the upcoming French Open, a move that amounts to a new installment in an ongoing battle between players and the four Grand Slam tournaments.

Then, on Tuesday, many of those same players discussed the prospect of a Grand Slam protest if their qualms aren't eased.

"I think at some point we will boycott it, yeah,” Sabalenka said during her pre-tournament press conference at the Italian Open. “I feel like that’s going to be the only way to fight for our rights."

But why exactly are the players so upset? What is at the root of this dispute, and how long has it been going on?…