The 28-year-old Tauchman made his major league debut in 2017 and hit just .153 in 59 at-bats in 52 career games with Colorado. Tauchman spent the majority of the 2018 season with Triple-A Albuquerque and hit .323 with 20 homers and 81 RBIs in 112 games.
Yankees manager Aaron Boone said Tauchman is an option to make the opening day roster.
''Can play multiple positions out in the outfield,'' Boone said. ''A guy that does have options, so we'll kind of talk through it and see which way we want to go.''
The 24-year-old Diehl, a 27th-round pick by the Yankees in 2016, attended spring training as a non-roster invitee and posted a 4.50 ERA with 17 strikeouts in nine relief appearances.
''A lot of emotions going through my mind,'' Diehl said. ''Got another opportunity to potentially pitch in the big leagues with the Rockies and I'm looking forward to it.''
To make room on the 40-man roster Saturday, the Yankees placed left-hander Jordan Montgomery on the 60-day injured list.
New York also re-assigned left-hander Nestor Cortes Jr., outfielder Estevan Florial and right-hander David Hale to the minor league camp.
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