Bobby Orr donated $90,000 to York University in Toronto recently toward development and construction of a sports injury clinic on campus. "I'm sure," said Orr, "a place like this would have helped me tremendously when I first started having problems with injuries. I'm going to get good use of it in the offseason."

For Orr as a player, the offseason became permanent yesterday. He gave up on what he said would be his last comeback try and retired to the posts of assistant coach and front-office aide on the Chicago Black Hawks.

Orr, signed by Chicago as a free agent in 1976 after 10 seasons with the Boston Bruins in which he established himself as probably the NHL's all-time great defenseman, played in only 20 games for the Black Hawks in 1976-77, none last season, and after a sixth operation on his left knee tried it in six of the first 11 games this season before giving up because he couldn't play anywhere near his standards. And what standards!

Suffice it to note two scoring championships, two goals and two assists this season for career figures of 270 G, 645 A.

He got a five-year, $3 million contract from Chicago in June 1976 - and has never cashed a paycheck. He said the contract was for him to play hockey and he has hardly done that. He is negotiating for a new pact, for less money.At only 30, Orr can look back on a lot of mileage on knee that began going bad as far back as 1968, when he had his first operation.

Nestor Chylak, 56, dean of major league umpires and one of the all-timers, has retired after 24 American League seasons on the diamond (health problems curtailed his 1978 campaign). He moves up to help supervise the AL umps . . . Congressional support for Washington baseball by California's 15th District should remain at a high level: Retiring Rep. Bernie Sisk's successor, via election Tuesday as a Democrat, is Tony Coelho, Sisk's administrative aide and liaison in bring-back-baseball efforts down through the years . . . The New York papers, after 88 days' shutdown, came out for the scalp of Don Grant as chief operating officer of the cellar-dwelling Mets. The Mets' stockholders tossed 'em most of bone yesterday: retained Grant as chairman until the end of the year and "shortly thereafter" - meaning, evidently, he'll be eased out via retirement come spring at age 75. He was in at the founding by the late Joan Payson c. 1962 and, interestingly, the stockholders now have declared of the current principal owner: "Mrs. Vincent de Roulet, president, will become increasingly active in the day-to-day management of the Mets . . ."