Terms were not disclosed, but Shreve will be guaranteed $1.5 million if he makes the major league roster, sources told ESPN's Jeff Passan.
Shreve, a left-hander, became a free agent when the New York Mets declined to offer him a 2021 contract by the December deadline.
Shreve, 30, was 1-0 with a 3.96 ERA over 17 appearances in his only season with the Mets, striking out 34 and walking 12 in 25 innings while allowing 17 hits.
Shreve, a left-hander, is a veteran of seven major league seasons with Atlanta (2014), the New York Yankees (2015-18), St. Louis (2018-19) and the Mets, going 17-8 with a 3.74 ERA in 235 relief appearances.
The Associated Press contributed to this report.