MILEPOSTS—NAMED: Player-coach of the Boston Celtics, Center DAVE COWENS, 30. A former NBA Co-Rookie of the Year and MVP, Cowens this season is averaging 17 points and 7.8 rebounds a game. He replaces TOM (Satch) SANDERS, 40, under whom the Celtics were 2-12 this year and 21-27 last season, after he took over from Tom Heinsohn on Jan. 5.
NAMED: National League Most Valuable Player, Outfielder DAVE PARKER, 27, of Pittsburgh. He led his league in batting (.334) and had 30 home runs and 117 RBIs.
SIGNED: By the New York Yankees, free agent LUISTIANT, whose age is variously listed as 37, 40 or whatever, for a reported $850,000. The righthander, who had a 13-8 record and a 3.31 ERA last season for the Boston Red Sox, will pitch for at least two years and then serve as the team's Director of Latin Affairs.