With four holes remaining in yesterday's second round in Georgia, Lee was sitting comfortably inside the top 10 at one-under for the tournament, but a pair of late bogies saw him drop to a share of 12th in the 30-man field.
It could have been much better for Lee, who started promisingly by making birdie on the fourth hole. But a double-bogey on the 10th undid the good work before further dropped shots on the 15th and 18th left him one-over par overall.
Lee will still be in line for a decent prize if he can maintain his position over the weekend, with the tournament boasting a mammoth $US8 million purse, but his cheque will pale in comparison to what is awaiting Henrik Stenson.
The Swede leads the tournament at the halfway mark, sitting on nine-under and three strokes clear of American Jordan Spieth. And with the Tour Championship doubling as the final leg of the FedEx Cup playoffs, Stenson is on track for a big bonus.
The world No6 led the playoffs heading into the tournament and, providing he maintains his form over the final two rounds, Stenson will receive a $US10 million prize to go along with his winner's cheque.
Meanwhile, fellow Kiwis Steve Alker and Tim Wilkinson are firmly in the hunt to retain their PGA Tour cards for the 2015-16 season. With Lee the only New Zealander to finish in the top 125 on the money list - currently sitting in 20th spot - Alker and Wilkinson were unable to automatically claim their cards.
Alker had four top-30 finishes to manage 185th on the money list with earnings of $US236,862, while Wilkinson finished nine spots further back after making only eight cuts all season to earn $US171,654.
But both Kiwis have a chance to retain their playing status on the major tour through the second-tier Web.com tour finals, a four-tournament series that rewards the top 25 earners with PGA Tour cards.
And Alker and Wilkinson are right in the mix during the third tournament of the four, the Nationwide Children's Hospital Championship. The Kiwis are 11th and 14th respectively at the halfway mark in Ohio, sitting right on the cusp of the top 25 overall.
