After diagnosing what ailed Mets' Edwin Diaz in 2019, Jeremy Hefner details plan to fix himThe main focus is on location5/7/2020, 6:30 PMMar 30, 2019; Washington, DC, USA; New York Mets relief pitcher Edwin Diaz (39) throws to the Washington Nationals during the ninth inning at Nationals Park. Mandatory Credit: Brad Mills-USA TODAY Sports / Brad Mills