Montas earned a spot on the A's Opening Day roster, Susan Slusser of the San Francisco Chronicle reports.
The A's are keeping eight men in the bullpen to start the season, which allows Montas to break camp with the big-league club. Montas made a strong case for a roster spot throughout the spring, allowing just one earned run over 11.2 innings while striking out 13 batters. The A's have yet to officially tab a closer, but veterans Ryan Madson, Sean Doolittle and John Axford are all likely ahead of Montas in the pecking order.