The Mets placed Diaz on the paternity list Wednesday.
Diaz is expected to remain away from the team for 1-to-3 days while he observes the birth of his child. The Mets called up Jake Reed from Triple-A Syracuse to give the team another arm in the bullpen, but Seth Lugo, Trevor May and Jeurys Familia are likelier candidates to receive looks as closer while Diaz is inactive.