Nicasio has a right knee effusion, a build-up of fluid around the knee joint. He is 1-3 with a 5.34 ERA, but he leads the American League with 14 holds.
Altavilla has a sprained right ulnar collateral ligament. He is 3-2 with a 2.61 ERA in 22 appearances. It's his second trip to the DL -- the last one was for an AC joint inflammation.
Nicasio and Altavilla join relievers David Phelps, who was lost for the season to Tommy John surgery; Nick Vincent, who went on the DL with a strained groin May 28; and Erasmo Ramirez, who strained his teres major, a muscle in his right rotator cuff.
The good news for the Mariners is that since May 16, their starting pitchers are 10-1 with a 2.24 ERA in 21 games. The team is 15-6 over that span. Mariners starters have gone at least eight innings in four games, at least seven in nine games and at least six in 15 games.
Starter Mike Leake, pitched into the ninth Thursday night, allowing the Rays only two runs on eight hits in a 5-4 win. "I think there is a little something to be said with how we are rolling right now starting pitchers," he said.
To take Nicasio's and Altavilla's spots on the roster, first baseman Dan Vogelbach was recalled from Triple-A Tacoma and the contract of right-hander Mike Morin was selected.