Sugar Ray Leonard's handlers evidently are a bit concerned their champion is cutting it a bit too fine too early in preparation for The Flight, June 20 against Roberto Duran.

After yesterday's training session in Montreal, adviser Janks Morton advised publicist Irving Rudd that workouts were off until Monday, and so were Leonard interviews, including a scheduled telephone session for which Los Angeles area media were set up.

At this stage, Leonard had been expected to be close to the 147-pound limit for his WBC welterweight title defense. When he finished yesterday's labors, the seales read only 144 . . .

Voluntary industry action is doing the job, the Consumer Product Safety Commission decided, and rejected yesterday a request that it establish safety standards for football helmets.

"The risk of head injury in competitive play has been reduced," said Commissioner R. David Pittle.

Tim McCormick has resigned as baseball coach at Catholic U., with three good years under his belt since he became -- at 22 -- the country's youngest pilot of a major-college program in the national pastime. The former CU catcher, captain and two-time MVP registered a .561 coaching percentage (86-67-2 with a school-record 24 wins this year). He says, "The fact that the school is reclassifying its athletic program to Division III (NCAA) had nothing to do with it" . . .

Purdue provided the NBA the No. 1 pick in the 1980 draft and it could happen again in four years -- or less. The prospective new Joe Barry Carroll is one of the most ballyhooed, and wooed, of the 1980 high school crop: 6-foot-10 Russell Cross from Chicago. PU isn't home free yet -- but Cross, after much indecision, has signed a Big Ten letter of intent with Purdue. While that only precludes going to another school in the conference, the Boilermakers' new coach. Gene Keady, is confident the big fellow won't enroll elsewhere: "Russell has given me his word and that's good enough for me."

Bill Lee, the Montreal pitcher, and jogging have proven a volatile mix two years in a row. Last year he was sidelined briefly after running into a car; now he's 21-day disabled after hurting his hip when, startled by a cat, he bumped into a fence . . .

Hors de tennis combat: Guillermo Vilas. He faces an appendectomy today in American Hospital, Paris: has withdrawn from upcoming Wimbledon.

Prospect for the Dallas NBA coaching post: Les Habegger, assistant to Lenny Wilkens at Seattle. Given Sonic permission to talk Maverick turkey, Habegger says, "I don't want to go down there as just another person they've talked to" . . .

Look for a retirement announcement by the weekend from Carl Eller, the 15-year Minnesota Viking Purple People Eater whose 16th NFL season was spent in Seattle. So says Eller, with only the shadow of a hedge . . . Roy White, the 15-year New York Yankee outfielder, whacked three homers for the Yomiuri Giants against Hiroshima yesterday -- in the same game in which teammate Sadaharu Oh bashed No. 850 . . .

Evidently a Yankee-to-be: Billy Cannon Jr., 6-4, 200-pound short-stopping son of LSU's 1959 Heisman Trophy halfback. Young Cannon, all-state in both football and baseball at Broadmoor High in Baton Rouge, where Cannon Sr. is a dentist, is to meet today with Yankee representatives, according to his mother. The yanks evidently didn't flinch at Cannon Sr.'s statement before last week's draft that Billy Jr. wouldn't sign for anything less than a bonus of $250,000 . . .

The National Multiple Sclerosis Society puts added kicks in its 1980 campaign by switching from the annual Dinner of Champions to "MS Day at RFK," in conjunction with Sunday's Dips-Fort Lauderdale game.For $25 adult, $15 children, 13-and-under, tax-deductible, patrons benefit MS; get in on 2 p.m. pregame festivities, the 2:30 game and 4:30 "meet the champions" buffet with Redskins, Bullets, Caps, Dips, Strikers, etc. in the Locker Room at the stadium. Call MS' National Capital Chapter about it.