Outgoing baseball commissioner Peter Ueberroth may make a bid to buy crippled Eastern Airlines as early as Wednesday, according to officials of the Air Line Pilots Association in Miami. The leadership of the pilots union was waiting for word from the board of Eastern's parent company, Texas Air Corp. of Houston. Spokesmen for ALPA said the union was guardedly optimistic about the prospects for such a deal. "We feel he (Texas Air Chairman Frank Lorenzo) desperately has to unload this airline," said an ALPA spokesman.