MIAMI - Tiger Woods described himself as in "competitive shape" for next week's US Masters after playing a practice round at a rain-sodden Augusta National Golf Club earlier this week.

The American world number five, a four-times champion at Augusta National, was surprised by how long the par-72 layout played and noticed subtle changes on the greens at the 11th and 17th.

"It was 40 degrees (4.44 degrees Celsius) and the course was soaked after three inches of rain the night before," Woods said on his official website.

"It's the most grass I've ever seen on the golf course. If they use the back tees, they could make it play really long."

Woods, a 14-times major champion, has not triumphed anywhere since the 2009 Australian Masters but has been encouraged by his improving form since the start of this year.

"I'm in much more competitive shape, no doubt," said the 35-year-old, who played his Masters practice round this week with his good friend Arjun Atwal of India. "I've got a good feel for what I'm doing and have more rounds under my belt."

Woods's game suffered as he tried unsuccessfully to repair his deteriorating marriage last year while spending less time at practice than usual.

His divorce from his Swedish wife, Elin Nordegren, was finalised in August, and that same month he embarked on the fourth swing change of his professional career, with Canadian coach Sean Foley.

"Early in the year was disappointing because the conditions showed some signs of weakness that I had to work on," Woods said after tying for 24th at last week's Arnold Palmer Invitational. "Now, it's feeling very, very good."

Woods, who won the most recent of his four Masters titles in 2005, said he noticed several changes to Augusta National, most notably a re-contouring of the 11th and 17th greens.

For the rest of this week, he will complete his Masters preparations in Albany in the Bahamas because of rainy conditions forecast in Orlando where he lives.

The 75th Masters will be played from April 7-10.