The 2017 AL MVP was injured in a collision at home plate in the fourth inning of the 15-6 win that was the Astros' last tuneup before their opener on Friday against Seattle. The team said he is listed as day to day.
Altuve hit .298 with 31 homers and 74 RBIs in 124 games last season while missing time with leg injuries.
He was one of three Astros who were hit by pitches against the Royals. Kansas City right-hander Jorge Lopez plunked Altuve and Alex Bregman, and George Springer was hit by Jackson Kowar, who took the loss.