Rickie Fowler was outside the FedEx Cup top 70 when he arrived at Royal Portrush to play in the Open Championship. In just three starts, he earned a spot in that group for the FedEx St. Jude Championship, and he's only gotten better since.In the first playoff event, Fowler climbed 16 spots in the FedEx Cup rankings to break into the top 50 and qualify for the BMW Championship. At Caves Valley, he's on the verge of completing a legendary comeback that could see him reach the Tour Championship.The six-time PGA Tour winner is tied for eighth at Caves Valley, projecting a 32nd-place finish in the rankings. However, if he improves just one spot on the leaderboard, his inclusion in the top 30 is almost certain. If he improves two spots, it's a done deal.Nevertheless, Fowler knows what he needs to do: focus on the round ahead this Sunday."Yeah, not in a bad spot," he told reporters after the third round. "We obviously have a chance going into tomorrow. In a way, I'd much rather be on the outside looking in. I know what I need to go do ... Go out and yeah, we'll see if we can get things going and hopefully get off to a nice start and just play some good golf tomorrow.""Obviously top five I know will lock it. There's a few other factors outside of that depending on finish from there. But go put together a nice round tomorrow and we'll be good."A top-30 finish at the FedEx Cup would give him a spot in the TOUR Championship field next week, but would also qualify him for next season's Masters Tournament, a spot he currently hasn't secured.Fowler shot 67, 70, and 67 at Caves Valley for a 54-hole score of 6-under. With just 18 holes remaining, Ludvig Aberg and Harry Hall round out the top five at 8-under.If he cracks the top 30 at the FedEx Cup rankings, it would mark Fowler's return to the Tour Championship after failing to qualify last season. In seven previous starts, he has two top-10 finishes, and his best result was a tied-for-7th finish in 2018.More Golf: Robert MacIntyre Reveals 'Head Down' Advice Received from Andy Murray