(Reuters) - Phil Mickelson has been a little rusty with his usually renowned short game in his first PGA Tour event in four months and he squandered the chance to shoot a low score at the Humana Challenge with some untidy play on Saturday. Though the American left-hander piled up eight birdies in the third round, he also carded four bogeys to finish with a four-under-par 68 on the Palmer Private course at PGA West. "The little nuances of getting the ball in the hole have been slightly off but it was a day today that could have been really low," Mickelson told Golf Channel after finishing at 11-under 205, six strokes off the tournament lead. "But I am looking forward to tomorrow's round and getting that one more round under my belt of competitiveness and see if I can get it all to kind of fire." Five-times major winner Mickelson has not competed on the PGA Tour since he withdrew from the BMW Championship after two rounds in September, saying he wanted to rest for the Ryder Cup that was played later that month.