LOS ANGELES (REUTERS) - An out-of-sorts Jordan Spieth had trouble identifying the reason for the swing problems that led to his downfall in the round-of-16 at the WGC-Dell Match Play in Texas on Saturday.
The world number one, who will defend his Masters title in a fortnight, battled his swing from the moment he stepped on to the range to warm up at Austin Country Club.
It did not get much better once competition began, as South African Louis Oosthuizen defeated Spieth 4&2.
It was another troubling performance by the Texan, whose consistent brilliance from last year has given way of late to a series of poor rounds that seemingly have occurred out of the blue.
"I had great ball control the last three days, played very, very solid rounds, and I got to the range this morning and I was hitting some slices with my irons, which is bizarre," the 22-year-old told Golf Channel.
"I never really get that. I tried to fix it on the range. I didn't really know what was up. I just tried to compensate some on the golf course, got away with it the first couple of holes and then it got the best of me."
Spieth, who previously this year had posted rounds of 76 (Valspar Championship), 79 (Northern Trust Open) and 74 (Pebble Beach Pro-Am), admitted it was a troubling trend ahead of Augusta.
"I'm not really sure what happened. Just an off day. I'd like my off days to be a little more consistent than they have been of late.
"It's frustrating when you're so uncomfortable over the ball and you're trying to commit to these targets."
Spieth has one more event before the Masters to sort out his issues. He is entered for the Houston Open starting on Thursday.