Diaz was removed from his position as the Mariners' closer Tuesday, Ryan Divish of The Seattle Times reports.
Although he has seven saves, the 23-year-old has been anything but tidy in his appearances this season, posting a 5.28 ERA and a 1.37 WHIP in 15.1 innings pitched. After two straight messy outings, manager Scott Servais opted to give Diaz a break from the role in order to work on his mechanics in lower-leverage situations. No clear frontrunner for saves has been revealed at this time, although Nick Vincent, Steve Cishek, Marc Rzepczynski and Tony Zych seem like candidates to fill the void for the time being.