Rory McIlroy to get MRI scan amid concerns that rib injury has returned
Danny Willett and Rory McIlroy are doubtful for the BMW PGA Championship after suffering from ongoing back problems in the Players Championship.
Willett admitted his body and mind need a rest after being forced to withdraw from the £8.1million event, the former Masters champion retiring after nine holes of the second round.
And McIlroy then revealed he would have an MRI scan on Monday to determine the extent of his own back problem, with the world number two admitting the "most important thing" is to be fit for June's US Open.
The BMW PGA Championship takes place in a fortnight's time and has a prize fund of £5.4million as the first event of the European Tour's Rolex Series.
"Hopefully, touch wood," Willett said when asked about his prospects of competing at Wentworth. "We'll see how things go.
"I've already limited the schedule down a lot, obviously all of the travelling we've been doing, and everything that's been going on. Hopefully, all going well, we get back on. We have a week to do some work and see how it feels."
Willett, who has been hampered by back problems throughout his career, struggled to an opening 79 on Thursday and had covered the back nine at Sawgrass in 40 before calling it a day.
The 29-year-old from Sheffield wrote on Twitter: "Not good to have to withdraw but swinging very poorly is putting a lot of unwanted strain on the back.. body and mind need a rest!!"
In quotes reported by the Golf Channel, Willett also told reporters at Sawgrass: "We woke up this morning and it was tight. I don't really need to see anyone else to tell me, I've had it many a time before."
Willett has slipped from a career-high of ninth in the world to his current position of 21st after a string of poor results, including becoming the first defending champion since Mike Weir in 2004 to miss the cut at Augusta National.
He also made an early exit from his next event in the RBC Heritage, where he split with long-time caddie Jonathan Smart after the first round.
McIlroy's injury is a combination of the back and rib problem which kept him out for seven weeks at the start of the season, although he was able to add a 71 to his opening 73 to reach halfway at level par, just five behind clubhouse leaders Rafa Cabrera Bello and David Hearn.
"I hit a couple of tee shots practising on Monday and just didn't feel right and I've been getting treatment on it," McIlroy told Sky Sports. "We just hope it's not the same thing, the joint and the rib.
"It feels more like a muscle strain so I'm going to get an MRI scan on Monday after the tournament and I might have to rest for a week or two. As long as I get myself right for the US Open, that's the most important thing."
Speaking about a round containing two birdies and one bogey, the newly-married four-time major winner said: "Today it seemed like the golf course should be gettable but no-one really posted any low numbers.
"It was tough to get close to a lot of the pins and I only birdied one of the par fives. Overall it was okay; I can't believe I'm only five off the lead and I can go out tomorrow morning, hopefully post a good score and get myself right back into the tournament."
Masters champion Sergio Garcia and world number one Dustin Johnson were alongside McIlroy on level par after rounds of 71 and 73 respectively.