The parade begins. Two of the Big Ten's best pro basketball prospects, 6-foot-10 Russell Cross of Purdue and 6-4 Derek Harper of Illinois, announced yesterday they will be available for the June 28 NBA draft and give up their senior seasons.

Cross' attorney "counseled Russell against the move if it was solely because of the new agreement" (NBA pact to restrict payrolls starting a year hence). Cross cited family needs; he lives in Chicago with mother, two brothers and three sisters.

Illini Coach Lou Henson tried to discourage Harper: "Most people seem to think he'll be drafted late in the first round or early in the second and that usually means a one-year guarantee. If he'd wait a year, though, he'd probably go in the top 10 and get a three-year guarantee" . . .

Mychal Thompson missed the Portland team flight and Monday practice for last night's game, and Coach Jack Ramsay fined him $500--while L.A. Coach Pat Riley was knocking the Blazer big man for knocking around Kareem Abdul-Jabbar in the playoffs. Thompson commented, "Not me. I don't want to do that. I've seen Kareem in a Bruce Lee movie" . . . During the Milwaukee-Boston set, Bucks Coach Don Nelson put the rap on Danny Ainge for supposed cheap shots on his players driving for the hoop--said maybe Ainge had given Atlanta's Tree Rollins good cause for mayhem. Now Celtics' Red Auerbach raps Nelson's talk as cheap --"he says something like that about a kid who can't do anything to fight back."