Three American Football Conference teams will have extra choices in the first round of the NFL draft April 28-29.

The New York Jets received a No. 1 pick from Denver for 24-year-old quarterback Matt Robinson; New England got a first-round choice from Houston for 28-year-old offensive tackle Leon Gray and Baltimore picked up a No. 1 from Dallas for defensive end John Dutton, a bequest from the former coach, Ted Marchibroda, to the new coach, Mike McCormack.

The only NFC team with an extra pick in the first round is Green Bay, from San Diego for defensive back Willie Buchanon.

Fortified with those extra selections, those four teams are in position to trade with Detroit, for its first choice in the whole draft, or with San Francisco for its second choice.

Some scouts are concerned about the age of Oklahoma's Billy Sims, 25, and the weight of Southern California's Charles White, 185.

A fan and student of the Jim Tatum era at the University of Maryland reminds us that in addition to 10 former Terrapin players being assistant coaches in the National or Canadian football leagues, onetime defensive back Dick Nolan is head coach at New Orleans and former quarterback Stan Lavine is the team physician for the Redskins.

Paul Krause, onetime Redskin free safety who was traded to Minnesota for linebacker Marlin McKeever and a No. 7 draft choice in 1968, is an absolute free agent after 16 seasons, having received no qualifying offer from the Vikings. He is 38 and the all-time NFL pass interceptor.

Defensive tackle Otis Sistrunk, 32, and from the "University of Mars," as former sportscaster Alex Karras once put it, is another free agent with no strings attached. The Oakland Raiders did not exercise their option to keep him.

Of 139 veterans whose contracts expired on Feb. 1, 26 did not receive qualifying offers from their former employers and eight did not have the option years on their contracts picked up, resulting in those 34 becoming free agents. Seven others have signed on again with the same teams.

The NFL would like Steve Rosenbloom to sell as soon as feasible his 6 percent of the stock in the Los Angeles Rams, to remove any possible conflict of interest as a result of his being hired as vice president and general manager at New Orleans. The Rams have 4,000 new seasons ticket orders since announcing their move to Anaheim for the 1980 season, plus their good showing in the Super Bowl.

The NFL does not plan to expand before knowing after the 1981 season what the new labor contract will entail, but Oakland's flirting with the "open city" of Los Angeles is reviving the topic. Vacant cities such as Oakland, Phoenix, Birmingham, Memphis, Jacksonville and Indianapolis would tempt investors to contemplate a new league.

Sounding like George Allen, Coach Red Miller of Denver says of giving up a No. 1 draft choice for the Jets' Robinson, "We already have made our first-round pick. Drafting 20th, we wouldn't have gotten a shot at a quality young quarterback like Robinson."