9th Don Baylor signs a one-year contract with the A’s.
St. Louis Cardinals trade Ricky Horton, Lance Johnson and cash to the Chicago White Sox in exchange for starter Jose DeLeon. DeLeon will win 29 games in the next two seasons for the Birds.
10th The Reds bring back Ed Milner, signing the free agent who played a year in San Francisco.
12th The Padres trade reliever Rich Gossage and Ray Hayward to the Cubs for OF Keith Moreland and Mike Brumley.
15th The Kansas City Royals swap Van Snider to Cincinnati Reds for Jeff Montgomery. Snider will play little in his two years in Cincy, while Montgomery will play 12 years in Kansas City, winning Fireman of the Year in 1993.
18th The Padres sign veteran SS Dickie Thon, released by Houston last month.
23rd A committee of Chicago aldermen vote 7-2 to allow the Cubs to install lights and play up to 18 night games a year at Wrigley Field. The Cubs had feared losing the 1990 All-Star Game, as well as future playoff and World Series games, if lights were not installed.
27th Veteran Ray Knight is traded from Baltimore to Detroit for P Mark Thurmond.