Wentworth: Paul Casey has warned Rory McIlroy and the rest of the field at the PGA Championship they best not underestimate him on his return to competition from a back problem.

The 2009 PGA winner has been suffering from an inflamed back joint and had to withdraw from Players Championship earlier this month and has since undergone therapy for the ailment.

It was frustrating for the 40-year-old Englishman as he had been in good form on the US Tour this season, the highlight a win in the Valspar Open by one stroke from Patrick Reed, who was to go on and win the Masters a few weeks later, and legend Tiger Woods.

Casey, whose best performance in a major was tied for third in the 2010 British Open, said the adage of beware the injured golfer could apply to him.

“Yes. Normally injured golfers are somewhat prepared,” said Casey on Wednesday.

“Yeah, I’m genuinely excited. I’ve been looking forward to this for a long time and when we looked at the schedule and I rejoined the Tour, you know, this was an obvious event that I was going to put in.

“With my past successes around this golf course, the quality field, you know, its stature in the world of golf is so important to me, and the fact that it’s home and it’s where I grew up, right around the corner in Weybridge.”

Casey, who is seeking a 14th European Tour title, said it was watching golfing greats perform in the PGA Championship that inspired him to take up the sport.

“This event is really one of the main reasons why I became a professional golfer, coming down here and watching Seve [Ballesteros] and [Sandy] Lyle and Woosie [Ian Woosnam] and [Bernhard] Langer and all those guys when I was a kid growing up.

“It has a special place in my heart, so yeah, I can’t explain how cool it is and how, touch wood, will be good for tomorrow to tee it up again.”

Casey, who admits he has missed being able to work out whilst he has undergone the therapy, says qualifying for the European Ryder Cup team for the first time in ten years — he was a member of two winning teams in the three he played in — is a major ambition this season.

This year’s Ryder Cup is being staged at Le Golf National near Paris from September 28-30.

“It’s always motivation,” said Casey.

“It’s always one of the big goals that I’ve written down but it’s compartmentalisation.

“I mean, it’s why, you know, why I’m doing this. I want to be on that team.

“I want to contribute to Europe and win that Cup back, plain and simple, and I believe I can be a big part of that.”