The Mariners were unable to unseat one of the hottest teams in the National League and further reaffirmed the need to improve at the trade deadline.

Right-handed pitcher Luis Castillo is scheduled to take the mound for the Mariners (54-47) at T-Mobile Park in Seattle. His earned run average in his last three appearances is just 1.45. Right-hander Quinn Priester will pitch for the Brewers (60-41). His ERA in his previous three appearances is 3.24.

The Seattle Mariners face the Los Angeles Angels in the opener of a 4-game set at Angel Stadium in Anaheim Thursday.