Jon Rahm begins title defense, LIV players contemplate Ryder Cup and more from the golf world

[www.espn.com - GOLF]

Nelly Korda is back at No. 1 and Chase Koepka inadvertently sparks a Twitter war. Here are the storylines to watch this week as the Mexico Open, JM Eagle LA Championship and LIV Golf Invitational Singapore get underway.