Walker went 1-for-4 with a solo home run in Tuesday's 5-1 loss to the Rockies.
Walker's opposite-field blast off Kyle Freeland in the second inning proved to be the Astros' lone run in the defeat. The first baseman has gotten off to a fast start this season, logging at least one hit in 10 of his first 12 games. In his last four contests, Walker's gone 7-for-19 with three home runs and a 1.323 OPS.