Els missed five months of last season with a knee injury

The world number five missed five months of last year but after a slow start he says he is ready to challenge.

Bay Hill features seven of the world's top 10 as golf's elite ramp up their preparations for the Masters.

"I know where I am with my game. I know where I am with my knee. I'm ready to step it up a little bit now," said Els.

The 36-year-old South Africa began the season promisingly with a play-off defeat to world number one Tiger Woods in the Dubai Desert Classic in February.

Since then he has tied for 23rd in the Nissan Open, finished tied seventh at Doral and lost in the first round of the WGC-Match Play Championship.

But he admitted he has been focusing on reaching his peak at the Masters, which begins on 5 April.

Woods has won three times in five starts this season

"I really want to get back into winning tournaments and competing, play the way that I know I can," he said ahead of the Bay Hill event, held at Arnold Palmer's club since 1979 and unofficially known as "Arnie's tournament".

"They [Els' team] keep on reminding me, 'Listen, we're not worried about now; we're looking at the second week of April'.

"Let's crawl before we have to walk, that kind of thing. But as a competitor, it's hard to explain. You just want to be there. You want to be in the mix all the time."

Also competing in Florida are Retief Goosen, Vijay Singh and Sergio Garcia from the world's top six.

But defending champion Kenny Perry will miss the event after knee surgery.

Ominously, though, Woods won four straight times at Bay Hill until 2003 and has triumphed three times in five starts this year, twice in America and once on the European Tour.

"It's one of those golf courses that fits your eye," said Woods of Bay Hill, where he also won the first of three straight US Junior Amateur titles.

Not one player on Tour has the philosophy of just going out and hitting all over the place Ernie Els

The field will also have to contend with Bay Hill rough which will be thicker than normal at four inches.

Palmer, a seven-time major winner, is delighted with the overall condition of the course and is hopeful that the rough will penalise big hitters who lack accuracy.

"It is the best this year than it has ever been," the 76-year-old said.

"We have not increased the length of the golf course. We'll watch the scores, let the rough grow up a little bit, let the greens get a little faster and a little harder and see what happens."

Els, champion in 1998 but only 23rd last year, backed Palmer's decision to grow the rough.

"We play with the best equipment and I think we should play on the best, toughest golf courses possible," he said.

"If you hit the ball a long way, you should be reasonably accurate.

"Not one player on Tour has the philosophy of just going out and hitting all over the place. It might work out that way, but we try and aim, get it in the fairway and give ourselves the best opportunity to make birdie."