Rain and wet grounds forced postponement of tonight's scheduled game between the Baltimore Orioles and New York Yankees. The game will be played as part of a doubleheader Sunday, starting at 2 p.m.

The Orioles also announced that outfielder John Lowenstein was placed on the 15-day disabled list. He sprained his left ankle severely Thursday night against Milwaukee when he crashed against the left field fence chasing a fly ball.

Pitcher Jim Palmer was reactivated to fill Lowenstein's spot on the roster. Palmer has been bothered by arm trouble.

Tonight's game was stopped after a 1-hour-25-minute delay after the Yankees had come to bat without scoring in the top of the first. The Orioles were awaiting their turn to bat.

Scheduled to pitch Sunday for the Orioles is either Scott McGregor (7-3), tonight's starter, or Sammy Stewart (7-5) in the opener and Dave Ford (1-0) in the second game. The Yankees will go with Luis Tiant (8-6) and Ron Guidry (10-7). The twin bill will wrap up the season series between the teams.

About 12,000 general-admission tickets remain for Sunday's games. However, holders of tickets for tonight's game (45,000 advance sale) can redeem their rain checks for Sunday's games. The ticket window at Memorial Stadium opens at noon.