Rory McIlroy finished solo 66th in the FedEx St. Jude Championship — the first stage of the FedExCup.

The PGA Tour superstar failed to break par in each of his four rounds at TPC Southwind, going 74-70-72-72 at the par-70 course in Memphis.

McIlroy expressed concern regarding the current state of his game following his final round on Sunday.

"Obviously didn't come in here with a ton of reps. [It] almost felt like the more the week went on, the more I felt lost with my golf swing a little bit," McIlroy said, via ESPN.

"The swing wasn't in sync and obviously I didn't do a ton of practice coming in here. I'm so far away from where I need to be to even feel like I have a chance. I've just got to keep working and hope it turns around a little bit."

McIlroy will look to bounce back in this weekend's BMW Championship at Bellerive Golf Course.

"I guess nice to shake the rust off a little bit, but I'm going to have to work pretty hard between now and next Thursday to feel like I have any sort of golf game to compete next week," he added.

"To me it's more about obviously the execution of what I'm doing right now, and the execution wasn't there this week. I'm going to have to sort of put the head down and grind from now until Thursday to try to feel like I have any sort of chance [at Bellerive]."