PITTSBURGH — The Pittsburgh Pirates had to open a spot on the roster for when they bring up Konnor Griffin ahead of their home opener. The Pirates announced that they optioned outfielder Billy Cook to Triple-A Indianapolis on April 2, which will allow them to add Griffin to the 26-man roster before the series with the Baltimore Orioles at PNC Park, April 3-5. Pittsburgh still needs to make room on the 40-man roster for Griffin and will designate someone for assignment before first pitch of the home opener. Cook made the Opening Day roster for the first time in his career, but hardly played in the first six games with the Pirates. He featured in three games, the final two games in the first series of the season vs. the New York Mets at Citi Field, March 28-29, and then the series opener vs. the Cincinnati Reds on March 30 at Great American Ball Park.…