Shortly before Thanksgiving, astute Eagles watchers sensed a profound change in Dick Vermeil. The day after a loss, he lingered long enough for a ham and cheese sandwich and a glass of milk with some reporters after a weekly press conference he had always bolted before all his words could be digested.

Vermeil even discussed a topic or two in addition to what had consumed him for half his life, and from which he escaped the other day: football.

There are others in sport more driven than Vermeil, but not many. In the second or third year of doing more with less than anyone in the National Football League, he returned from one of those glittering dinners where attendance was mandatory. Someone asked who had sat next to him on the dais.

"Don't know," he said. "Some baseball guy. Think it was an Oriole pitcher. Do those guys have somebody named Palmer?"

They certainly do, and Vermeil just might get to know his full name by spring training. Of all the moves in a brilliant career, Vermeil's best very likely was knowing both flames on his inner candle finally had met, that after 23 years he was "emotionally burned out."

You feel sorry for such as Vermeil, whose routine three nights each week of each of his seven Eagles seasons was sleeping on an office cot, if at all. His wife Carol would meet him at the studio each Thursday evening and hand over the suit she had chosen for him to wear on his television show. Their only dinner together would be Friday.

Pretty shallow for a man in one of mankind's lesser callings. And yet there also is more than slight admiration for him here. So much energy. So much purpose. How grand it would be to fix on something, however inconsequential, and test the limits of mind and will.

The Eagles teams seemed to reflect their coach. When they won, it was largely because they outworked the opposition. Vermeil had no high draft choices his first three years. Oddly, when he had some first- and second-rounders, the team began to slide. It made the Super Bowl after the 1980 season, but lost seven of its most recent 11 games over two years.

Like Vermeil, their zest may be drained.

Charlie Johnson all but said so during training camp, demanding to be traded because he no longer could tolerate being pushed so fiercely and being accommodated. That is said to have hurt Vermeil deeply. Also, the players' strike stuck him hard. He got a chance to think: if football wasn't everything for football players, maybe it shouldn't be for him.

Vermeil thought it time to smell the roses not long after suddenly being fascinated by leaves. Eureka, he realized, things besides dropped passes flutter to earth in the fall.

During the strike, Carol said, they had time to travel by car "and Dick discovered that leaves really do change. He took maybe 100 pictures. All along, he'd thought the world was green, with white stripes."

Vermeil will try what a lot of colleagues do when they want to take the rest of their lives off: sports commentary on television. John Madden found that an adequate release when he kicked the NFL coaching habit. George Allen thought it too confining when the NFL wouldn't let him back in.

Eventually, Vermeil may be reenergized and return to the game at its highest level. But not in fickle Philly, he insisted.

"I wish I had the (Don) Shula or (Tom) Landry personality," he said during his final, emotional press conference Monday. "They appear to be able to turn the highs and lows on and off. My problem is that the highs don't last very long and the lows last for hours and days.

"It has a grinding effect on you and it's a drain on you and a deterrent in you being as good a football coach as you should be. And I'm only interested in being the best at whatever I do . . . All I've done (the last few years) is kept adding hours to the day.

"The person that I am, I'm my own worst enemy."

As players' bodies can stand only a finite number of collisions, so coaches' minds can tolerate only so many Xs bouncing off only so many Os. Two other credits to the profession--last season's genius, Bill Walsh, and the Bills' Chuck Knox--also are weighing career changes. Walsh said yesterday he would step down as coach and retain the general manager's job if he could find the "right man" to replace him on the sidelines.

Meanwhile, the most misunderstood coach of them all, Harry Peter Grant, is burning brightly, after 26 years, not burning out. His Vikings are the next hurdle over which the Redskins must leap on their journey to the Super Bowl.

In 11 years with the Canadian Football League and 15 with the NFL, Bud has managed to win and manage a life beyond football. His teams are as prepared and inventive as any; their coach also works at play. And at establishing a daily family routine, at home.

Grant's other passion, his football release, is the outdoors. Frequently, he comes to the office from some duck blind; sometimes, his dog can be seen relaxing on the sideline during practice. When the game plans were prepared, but no games could be played during the strike, Grant would hustle to the wilds of South Dakota or Wisconsin.

For Christmas, Grant's family gave him a deer feeder. He can turn from his desk and watch a small herd feast at it, in a marshland where mink and geese also reside. Having lost all four Super Bowls he has made as Viking coach, Grant seems better able to cope with priorities than many who snicker at him for that failing.

When the season ends for Grant, it ends. Some coaches wear beepers to the bathroom; Grant's cottage near Gordon, Wis., has no telephone. If there is a trade to be discussed, or some other significant matter, General Manager Mike Lynn knows to call the local bowling alley and leave a message. Bud drops by from time to time, to see how the world is turning.

Reacting to Vermeil's resignation Monday, Redskins Coach Joe Gibbs said yesterday he believed successful coaches leave the profession mostly "because of a pride factor. You reach certain goals, but when you hit on hard times, people are writing things and saying things; they are saying things to your children . . . That's what hurt those guys. It's a pride in what you are doing and then to have those things happen."

Gibbs said coaches "create their own monsters. If you aren't winning, people are saying, 'Hey, out.' When you start to win, you're expected to win from then on. Very seldom do you hear people say you do an average job . . . I don't worry about getting burned out. This is still a challenge to me; that's what I like about it. But you have to get it done fast, in two or three years. No one is giving you five or six years anymore."