"As I've said all along, I would pick Tiger Woods if he's healthy and playing well," Watson, the team captain, told SiriusXM PGA Tour Radio on Monday. "This doesn't bode well right now."
Woods has returned to Florida for medical evaluation. He underwent back surgery in the spring and was playing only his third tournament since rejoining the tour. An awkward shot from the edge of a bunker on No. 2 jarred his lower back, forcing him to withdraw from the tournament after eight holes.
His status for this week's PGA Championship remains in doubt.
Watson said he sent Woods a "get well soon" text.
"I just hope that maybe it's just an isolated problem that he can turn around and possibly play this week at the PGA," Watson said.