"As of now I am still entered into the BMW PGA Championship", said McIlroy.
The pain is only about half as bad as it was when he was forced to miss two lucrative events on the European Tour's Middle East swing earlier this year, but Rory McIlroy's increasingly delicate lumbar region is again not 100 per cent.
On Monday, McIlroy told Ewan Murray of the Guardian that the MRI confirmed no new injury to his back or ribs. I've just sort of been managing it since. "But there are so many unknowns and unless you get an image taken of it you just don't know".
"I had the injury, then I played three our of four events leading up to Augusta and then I took a little bit of time off".
Rahm is looking to become just the third player to win the Players in his first try, joining Hal Sutton (1983) and Craig Perks (2002). He said last week's pain was closer to "4 or 5". "I feel like I can distinguish what the difference is between the two, so it's about making sure there's no spasm and it doesn't really tighten up around the joint".
Dustin Johnson recorded his best-ever finish at the Players Championship
During The Players, McIlory was slowed by the recurrence of a nagging back injury, reaching behind to the bottom of his lower-left shoulder blade to show where he feels the twinge.
Once the fun ended, McIlroy hit the practice range last Friday and Saturday for several hours each day.
Rory McIlroy has never been happier off the golf course. Jon Rahm, a player whose star continues to rise at pace, signed for a 72 to remain at four under.
By close of play McIlroy's even-par aggregate was nine adrift of the leaders, Kyle Stanley and Louis Oosthuizen. "I have good momentum going into the weekend", Rahm said.