(Pittsburgh, PA)  --  After winning back-to-back series, a day off is probably the last thing the Mariners want.  After the off day today, they'll travel across the country to face the Pirates in Pittsburgh in the first of a three-game series tomorrow.  Marco Gonzales will take the ball Tuesday for Scott Servais' club.  The southpaw is 15-and-11 with a 4.30 ERA and won his last start.  Mitch Keller will take the ball for the Bucs in search of his second win for the season and career.  He's 1-and-4 with an 8.29 ERA in nine starts this year.  Justin Dunn and Yusei Kikuchi are scheduled to start the final two games of the series for the M's.