Diaz agreed Wednesday with the Mariners on a minor-league contract, Ryan Divish of The Seattle Times reports.
Diaz cleared waivers Friday and elected to become a free agent.
The Mariners designated Diaz for assignment Monday.
The Mariners optioned Diaz to the Spring Training Complex on Monday.
The Mariners recalled Diaz from Triple-A Tacoma prior to Sunday's 3-2 loss to the Angels.
The Mariners optioned Diaz to Triple-A Tacoma on Saturday.
Diaz (0-1) took the extra-inning loss against the Red Sox on Wednesday, allowing an unearned run on one hit over one-third of an inning.
The Mariners recalled Diaz from Triple-A Tacoma on Tuesday.
The Mariners optioned Diaz to Triple-A Tacoma on Tuesday, Ryan Divish of The Seattle Times reports.
The Mariners recalled Diaz from Triple-A Tacoma on Friday.