Collin Morikawa looks to be a doubt for The Masters after withdrawing from this week's Valero Texas Open.
The two-time Major champion was last seen at TPC Sawgrass, where he withdrew after just one hole after tweaking his back on a practice swing.
Three weeks later he was due to tee it up to get some final Masters prep at TPC San Antonio but he was confirmed to be out of the field on Tuesday morning. Frankie Capan III will replace him in Texas.
Morikawa remains among the favorites for the Green Jacket, having made 5/5 cuts with three top-10s at Augusta, but whether he will even be in the field next week is now up in the air.
"I felt fine in warm-up, nothing's been any signs of back problems," Morikawa said after WD'ing at TPC Sawgrass.
"And teed it up on 11, and took one practice swing, and I just knew it was gone. Like I just had the feeling before when it's happened. And I just, I can't swing through it. Trust me, I would play if I could. It's just the worst thing in the world."
The injury has been disappointing for Morikawa after a strong start to the year, which saw him win the AT&T Pebble Beach Pro-Am, finish 5th at the Arnold Palmer Invitational and T7th at the Genesis Invitational.
The former World No.2 is the latest player to withdraw from the Valero Texas Open after a number of field changes this week.
Daniel Berger also pulled out on Tuesday morning, following Houston Open winner Gary Woodland, Nicolai Hojgaard, Matti Schmid and Pierceson Coody all withdrawing on Monday.
That came after Ryan Gerard, Isaiah Salinda and Aaron Wise all also pulled out over the weekend.
The Valero Texas Open gets underway on Thursday, with Brian Harman looking to defend his title. It is the final chance for players to qualify for The Masters, with only the winner earning their spot in the field for the year's first Major.
Rickie Fowler, Billy Horschel and Tony Finau are among the notables vying for a chance to drive down Magnolia Lane.
