Hal McRae, baseball's leading designated hitter and RBI man last season, says chances are good that he will not return to the Kansas City Royals in 1983. McRae, a 36-year-old free agent, said in an interview with the Kansas City Star that the Royals rejected his proposal for a contract. He said there is "a 90 percent chance" he won't return.

McRae would not discuss terms of the contract he is seeking except to say he wants a three-year agreement at "the going rate" for designated hitters. Ken Singleton of the Baltimore Orioles is believed to be the highest-paid designated hitter at about $600,000 a year . . .

Shortstop Robin Yount is the only unanimous selection for the 1982 United Press International American League all-star team that includes three other members of the league-champion Milwaukee Brewers: first baseman Cecil Cooper, outfielder Gorman Thomas and pitcher Pete Vuckovich.

Rounding out the squad are third baseman Doug DeCinces and outfielder Reggie Jackson of the California Angels, designated-hitter McRae and relief pitcher Dan Quisenberry of the Kansas City Royals, catcher Lance Parrish of the Detroit Tigers, second baseman Damaso Garcia of the Toronto Blue Jays, pitcher Jim Palmer of the Baltimore Orioles and outfielder Dave Winfield of the New York Yankees . . .

St. Louis police say they're investigating a theft at the Sports Hall of Fame at Busch Stadium in which memorabilia belonging to former Cardinals great Stan Musial was taken . . .

NBC Research estimated that a record television audience of 80 million watched the Cardinals beat the Brewers in Game 7 of the World Series. "The game earned a 38.2 rating and was seen in 31.8 million households," a network spokesman reported.