McCann spent the last two seasons with the Astrosafter a trade from the New York Yankees in November 2016. McCann made $17 million last season in the final guaranteed year of a five-year, $85 million contract he signed with the Yankees in 2014.
The option would have become guaranteed if he accumulated 1,000 plate appearances combined in 2017-18, made 90 starts at catcher last season and been active at the end of the season. McCann, who missed two months this year after knee surgery, made just 62 starts at catcher and had 615 plate appearances in two seasons in Houston.
McCann hit just .212 with seven homers and 23 RBIs last season.