Michael Fulmer struggled in the nightcap of Saturday's doubleheader against the Mariners, allowing six runs over 4 1/3 innings in a loss.
Robinson Cano chased Fulmer from the game in the fifth when he hit a 3-run home run to make it 6-2 Seattle. After striking out to end the inning, he remained in the game to play right field.
Castellanos, 26, is hitting.326 with three home runs and 23 RBIs on the season.
The Tigers broke a 1-all tie in the sixth. He struck out three and walked two.
Rain picks up again Sunday night, severe thunderstorms possible
Showers and thunderstorms will begin again Sunday night and should last into the Monday morning commute. In the wake of the storms overnight, skies remain cloudy with lows around 53 degrees.
Detroit's pitchers have given up 4.6 runs per game overall in 2018 as a unit. The Tigers have hit eight over their last 10.
Three relievers finished the opener for Detroit, with Shane Greene pitching the ninth for his eighth save in 10 chances.
John Hicks and Pete Kozma each had two RBI to lead the Tigers in the second game. Warwick Saupold took the loss and is now 1-1 with a 3.00 ERA on the year. Detroit starter Francisco Liriano gave up three runs over four frames with Johnny Barbato allowing a run for a blown save before Warwick Saupold surrendered a walk off homer in the 10th. Boyd did not record a start against the Mariners in 2017. The Tigers are putting up 4.42 runs per game while allowing 4.64 per contest. The bullpen ranks 24th in the league with a 4.70 ERA. It may happen eventually, but not in this game. They have now dropped five of their last seven games.
The Detroit Tigers and the Seattle Mariners split a doubleheader on Saturday. He is 1-3 through six starts this season.
The Tigers have actually won seven of their last 10 home games, but just 4-10 in Boyd's last 14 home starts. "We had a miscommunication over the phone about it and I'm not going to point fingers".