Phil Mickelson cited fatigue and struggles with the putter as the primary factors in his disappointing finish to round two of the Masters, but remains optimistic he can still pick up a fourth title at Augusta.
In his 25th outing at the year's first major, Mickelson - the 2004, 2006 and 2010 champion - got to within shot one of the lead on Friday, only to record bogeys at the 14th, 16th and 17th and card a 73.
As a result, the 46-year-old will begin the weekend on level par - four adrift of Rickie Fowler, Sergio Garcia, Thomas Pieters and Charley Hoffman.
"It was a hard, difficult day. And I'm really tired," Mickelson, who will play with Jordan Spieth on Saturday, told reporters. "It was obvious there in the end. I played the last five holes very poorly after a really good round.
"But I'm even par through two rounds. I'm four back. I'm in a good spot heading into the weekend, just feel I should be a few more ahead."
Mickelson three-putted the 11th and 14th on a day when winds again made low scoring tricky, although calmer conditions are expected over the weekend
"I struggled with the putter today. And a lot of it was wind-based," Mickelson added.
"It's easy if you have to hit them. The wind is having more of an effect than the break is.
"Hopefully with calm conditions I'll get that thing dialled in tomorrow [Saturday] because I've been putting really well. And if I can have a good putting weekend I'm going to have a good chance.
"I'm in a good spot heading into the weekend. I'm playing well. I've been putting well other than today. And I'm very optimistic I'm going to make a good run. But right now I'm so tired I need to go rest up."