After blowing his chances at the Open at Muirfield last month with an 84 in the stormy third round, Colin Montgomerie has spoken of his frustration at the inconsistency of his game while preparing for the USPGA Championship.

Montgomerie played his first practice round at Hazeltine on Monday and had a light day chipping and putting today in preparation for the fourth and final major of the year on Thursday.

The 39-year-old will be hoping to be more consistent than at Muirfield, where he carded rounds of 74, 64, 84 and 75.

"My game is about eight out of 10 at the moment," said Montgomerie.

"Whether it will have to be 10 out of 10 to win we'll see.

"I would be more worried if I was shooting rounds of 75 all the time but there can't be much wrong because I am producing the odd low round.

"I just need three of them a tournament rather than just one.

"But it is totally frustrating, especially when I used to be so consistent.

"It's been a big change and no human being likes change. It has a lot to do with my back, and whether I can get through the ball.

"That's why I have started a two-year fitness programme which I am only a couple of months into. I still believe I can keep on improving."

Montgomerie was glad he had played in Sweden a fortnight ago after initially saying, as he left Muirfield, that he was pulling out because he "could not handle it".

He added today: "I was quite upset at the Open. I felt it was unfair.

"When I have done something I feel guilty and full of remorse.

"I have known people who have a worse temperament on the course than me in the last few years but I seem to get the rap. I was even slated for playing quickly."

He was full of encouragement for Justin Rose, playing in his first major in the States.

"He just needs to be patient. He is a very good player and if he can get off to a steady start he will be fine.

"Hopefully he will do well because he is one of our up-and-coming players.

"He will be in our next Ryder Cup team. He should be in this year's team but for the side already being selected."