Rory McIlroy admitted to feeling "rusty" after his back injury, but he remains confident of putting up a challenge in his Players Championship title defence.

McIlroy withdrew from the Arnold Palmer Invitational last weekend at the halfway stage, having struggled with a back injury, leading to him making a "game-time decision" on whether to tee up at TPC Sawgrass.

The Northern Irishman did not get in a practice round and finished with a mixed opening first day in which he mixed a birdie with three bogeys to card a two-over 74, which leaves him seven shots off the lead.

It was almost better for McIlroy, who saw birdie putts on the 16th and 17th holes graze the edge of the cup.

"It was fine," he said when asked how his back felt during the round. "The most discomfort was when the ball was below my feet or with chipping.

"But it's weird. I played on Friday; it's not as if I've taken a ton of time off, I just felt unbelievably rusty out there.

"I'm glad I got through the round. Honestly, I don't feel like I'm that far away. No one went really low, which I expected them to, just because the conditions were pretty benign. If I can go out and shoot a good one [on Friday], I feel like I'll be right in it for the weekend."

Game-time decision = made.

Rory is underway for Round 1 @THEPLAYERS! https://t.co/8rraSMhjez pic.twitter.com/e9tNCFsNHv

— PGA TOUR (@PGATOUR) March 12, 2026

There is a four-way tie for the clubhouse lead after Thursday's action, with Maverick McNealy, Lee Hodges, Sepp Straka, and Sahith Theegala all on five-under.

Austin Smotherman is also level with that group, but is one of four players yet to finish round one after a rain delay interrupted the day's action.

Tommy Fleetwood was among those to play in the worst of the weather and is just two shots back, tied for 10th, alongside the likes of Xander Schauffele and Ludvig Aberg.

World number one Scottie Scheffler, meanwhile, is chasing a third title at the Players, having triumphed in 2023 and 2024, but he endured an erratic start, with four birdies cancelled out by four bogeys as he opened with a level-par 72.

Meanwhile, Collin Morikawa withdrew from the tournament after just one hole.

"I felt fine in warm-up," he said of having to pull out. "Like, nothing's been any signs of back problems.

"And teed it up on 11, and took one practice swing, and I just knew it was gone. Like I just had the feeling before when it's happened.

"And I just, I can't swing through it. Trust me, I would play if I could. It's just the worst thing in the world."