An exclusive field of 73, headed by perennial favorite Jack Nacklaus and including Washington's Lee Elder and Richmond amateur Vinny Giles, will tee off in the 41st Masters golf tournament in Augusta, Ga., Thursday.

The 72-hole test over the 7,030 yards of the colorful Augusta National Golf Club course traditionally ushers in spring for the pro golfers, as well as inaugurating the first of the four major tournaments in the world. The others are the U.S. and British opens and the PGA Championship.

Elder is back at the Masters after an absence of a year. He earned his second invitation by winning the Houston Open last May. The Washington golfer, the first black ever to play in the Masters, says he's over the nervousness that marked his 1975 debut when he caught the attention of the sports world.

"I'm Lee Elder the golfer now and not a freak," he said last week on one of his visits home between four stops. "I liked what I saw of Augusta two years ago and I think I'm ready to play the caliber of game that earned me my spot."

There will be two notable absentees in the field of 51 American pros, eight amateurs and 14 foreign pros. Lee Trevino has withdrawn. The Texan, who has won the three other major titles, hasn't been at top form since a winter operation for a herniated disc. Another casualty is John Mahaffey, who barely missed winning the last two U.S. opens. Mahaffey has an elbow injury.

Giles, the former U.S. and British amateur champion who now is a lawyer-agent for many of the golfers on the pro tour, heads the list of amateurs.

No amateur has ever won the Masters. Three have finished second or tied for second - Frank Stranahan in 1974, Ken Venturi in 1956, and Charles Coe in 1961. Billy Joe Patton finished third in 1954, a stroke behind Sam Snead and Ben Hogan, who tied at 289. Snead won the playoff by a stroke.

"The Masters starts the season for me," says the 37-year-old Nicklaus. "I'm not quite as sharp as I'd like to be coming into the Masters but my desire is as sharp as ever." He is the 6-to-1 choice of the odd makers. At 7-to-1 are Hale Irwin, Tom Watson and Ben Crenshaw.

As always, this is a formidable field. On the American side are Watson, a onetime British Open champion who has won two tournaments this winter and finished second in another; Irwin the methodical shotmaker who is nearly always in contention; Tom Weiskopf who has been a runner-up in this tournament four times; Crenshaw, a veteran at 25 who was second to Raymond Floyd last year; Jerry Pate, the 23-year-old current U.S. Open champion, and Johnny Miller. Despite his poor showing this winter winning a little more than $1,000, Miller, who won't be 30 until April 29, ways of his chances: "Anybody with brains knows I'm not through."

The 40-year-old Gary Player, one of only four golfers to win the four major titles (he's won the Masters twice) is the favorite among the list of foreigners, but there is strong support for two Australians, Graham Marsh, who has won 26 foreign titles and recently registered his first U.S. victory in the Heritage Classic, and David Graham, who won two U.S. tournaments last year.

As usual, the crowd favorite will be 47-year-old Arnold Palmer, who has captured the Masters green jacket four times. Palmer hasn't won a major title since the 1964 Masters and his last U.S. tour victory was in 1973. But Arnies Army never seems to retreat.