Robinson Cano left Seattle's game at Detroit in the third inning Sunday with a broken right hand after being hit by a pitch. It's unclear how long Cano will be out.
Castellanos is hitting.326 with three home runs and 23 RBIs on the season.
In the first game, the Tigers scored three runs in the sixth inning to take a 4-1 lead, with the big blow being a 2-run home run by Jose Iglesias.
The Mariners announced later Sunday that Cano has a fractured fifth metacarpal.
Our models project Castellanos to hit.280 with 19 home runs, 56 runs, 65 RBI, and 2 stolen bases in 453 more plate appearances in 2018.
Three relievers finished the game for Detroit, with Shane Greene pitching the ninth for his eighth save in 10 chances.
Acta, normally the bench coach for Seattle, was managing because Servais was away to watch his daughter receive a master's degree at Mississippi.
Detroit purchased the contract of right-hander Louis Coleman from Triple-A Toledo.
Mariners: Seager was able to play on after Jones' double off his leg in the first game.
Veteran Felix Hernandez toes the rubber for Seattle Saturday against Detroit. He struck out seven and walked two.
The 25-year-old Altavilla was placed on the 10-day DL with right AC joint inflammation on May 1 (retroactive to April 30).
He stayed in the game after being checked out by Tigers head athletic trainer Kevin Rand but then was lifted for a pinch-hitter in the second inning. The team described his injury as a contusion. Blaine Hardy (0-0) starts for the Tigers.