Wheatcroft has become an exempt player on the tour twice in his career, but was unable to maintain his playing privileges on either occasion.
He was one of four competitors who earned their way into this week's event at Monday's 18-hole qualifying tourney and has taken advantage of the opportunity by firing back-to-back 67s at the Redstone Golf Club.
His 10-under 134 total gave him a one-shot lead over first-round leader D.A. Points and Jason Kokrak, who have combined to miss the cut 13 times in their 17 tour appearances this year.
Points, who shot a 64 Thursday, made one birdie and 17 pars Friday on his way to a 71 and a 36-hole score of 135.
Defending champion Phil Mickelson and Rory McIlroy, replaced as the world's No. 1 player this week by Tiger Woods, both barely survived the cut at 1-under 143. Mickelson birdied three holes in a row on the back nine during a round of 71, but suffered a double bogey for the second straight day.