American Billy Horschel won the tournament with a score of 14 under par for the week.
Charl Schwartzel, Ernie Els, and Tim Clark all failed to do enough to advance to the season-ending Tour Championship, in Atlanta, starting Thursday.
Only the top 30 players in the standings make it through to the final event of the regular PGA Tour season, and even a tie for 12th was not enough for Schwartzel to make the grade.
The 2011 Masters champion was the top South African in the event with a four round total of six under after rounds of 72 66 70 and 66. But coming into the week in 52nd spot on the standings, it left Schwartzel too much to do on day four as he ended in 43rd place.
Els, meanwhile, produced a consistent week with rounds of 70 69 69 and 67 for 16th place on five under, but his performance was also just not good enough to secure his berth into next week’s season climax. Even though The Big Easy reeled off three birdies in a row to finish off, he had to settle for and overall 41st place in the standings.
Clark battled his way to one over for the week after rounds of 71 69 70 and 71, and a tied 36th finish was never going to help his cause. The only South African winner on the PGA Tour this season ended the playoffs in 54th.
Clark secured his entry into the Cherry Hills playoffs with victory in the Canadian Open in July, but had struggled since then. His best place finish after the win in Montreal was a tie for 24th at the Wyndham Championship in August.
The player from Umkomaas was also forced to withdraw from the Deutsche Bank Championship last week as a persistent elbow injury flared up again.