Castellanos hit his third homer this spring, connecting against Yoervis Medina.
Aaron Harang, competing for a spot in the Dodgers' rotation, allowed two runs and six hits in three innings. In five innings this spring, he has given up six runs on 11 hits.
Franklin Gutierrez hit a two-run single off Harang.
Mariners right-hander Jon Garland worked three innings in his third appearance this spring, giving up one run on two hits.