The Rockies have a few pitchers that could be cut too.
Joe Harvey
Joe Harvey was just added to the Rockies roster as a result of Wade Davis being placed on the 10-day injured list so, on the pitching front, he’s an obvious candidate to be cut.
In his short stint on the 30-man roster, he has yet to make an appearance. In 2019, he pitched to a 5.63 ERA in nine relief appearances for the Rockies.
Ashton Goudeau
Like Diaz and Fuentes, Ashton Goudeau has been on the Rockies roster since Opening Day but he has yet to make an appearance. He hasn’t even made his MLB debut, in general.
He didn’t even pitch at the Triple-A level for the Rockies last season as he spent the entire season at Double-A Hartford. When Goudeau was in the Seattle Mariners organization in 2018, he made it to the Triple-A level but he pitched to an 8.20 ERA in 37 1/3 innings pitched.
Two other, less likely possibilities
James Pazos and Phillip Diehl are two other possibilities of being cut from the roster. However, both of them are less likely to be cut for one reason: they are left-handed pitchers.
With Jake McGee being cut by the Rockies prior to the start of the season, Pazos and Diehl are the only left-handed relievers in the Rockies bullpen. Perhaps, that is something that will be addressed before the August 31 trade deadline since the Rockies look like they may be in contention then.