Bryson DeChambeau refused to discuss injury problems despite noticeably struggling at the Farmers Insurance Open.
The world No.9 was repeatedly pictured grimacing as he flexed his left wrist, and on a few occasions released the club with one hand.
Two weeks ago he revealed he had been struggling with a wrist injury, citing it as the reason for his withdrawal from the Sony Open in Hawaii.
He admitted he had been dealing with the problem for several weeks, putting it down to the speed training he has been doing to add yet more distance.
Problems began to resurface for DeChambeau during his second round at Torrey Pines as he shot a 72 to miss the cut.
After the round, he refused interview requests, saying he was “not going to talk about” his injury.
However, it could mean uncertainty over his participation in next week’s Saudi International.
Meanwhile DeChambeau’s playing partner Jordan Spieth was suffering health issues of his own during the second round.
Having felt unwell for much of the week, he went to hospital on Wednesday evening and although he returned for day two on Thursday, admitted he felt “awful” and revealed he was due to pick up more antibiotics after speaking to his doctor.
He also missed the cut after shooting a 78, ending his streak of being there for 20 weekends in a row.