The season again found Oakland winning the AL West, this year with a 103–59 record, finishing ahead of the Chicago White Sox by 9 games. Henderson batted .271 with 20 home runs and 63 RBIs, while appearing in 127 games, including 100 complete games in center field. He missed 27 games between August 20 and September 21, due to torn cartilage in his right knee. Oakland met the AL East winning Red Sox in the 1990 ALCS and swept them in four games, as they had done two years prior. Oakland had Willie McGee in center field in the first two games, with Henderson playing the last two games. During those two games, Henderson batted 1-for-6 (.167) with one RBI. Oakland was unable to repeat as champions, being swept in four games by the Cincinnati Reds in the 1990 World Series. Henderson batted 3-for-13 (.231) without a home run or RBI. Oakland used McGee in center field in Game 1, with Henderson playing the other three games. Overall for the postseason, Henderson hit .211 (4-for-19) with one RBI and without a home run.