The media learned on May 16 that Marcos Mateo was in the hospital with pain in his left hip. He could be taken off the active roster depending on his condition.
Mateo first started feeling discomfort in the area about a week ago. He was able to pitch through it, but his condition did not improve and he was taken to a hospital after his outing against Yokohama on May 15 for tests. He is currently considered day-to-day. If his condition does not improve with a couple days of rest, the Tigers could opt to take him off the active roster.
If Mateo is taken off the active roster, Rafael Dolis could take over as closer. The move would also open a spot on the active roster for Matt Hague.
Source: Sanspo 5/17/2016