Santiago was designated for assignment following Friday's game against the Cardinals after allowing one run on one hit and one walk over one inning, Anthony DiComo of MLB.com reports. Santiago has given up a run in five of his eight appearances this season, so the Mets have elected to boot him off the 40-man roster. He'll head to the waiver wire, though he appears unlikely to draw much interest given his recent struggles.
Santiago had his contract selected from Triple-A Syracuse on Monday, Tim Healey of Newsday reports. Santiago will replace Seth Lugo (shoulder) -- who was placed on the injured list Monday -- on the 25-man roster, while Jed Lowrie (hamstring) was shifted to the 60-day IL to free up a spot on the 40-man. The veteran right-hander has worked primarily as a starter in the minors this season, compiling a 3.35 ERA, 1.28 WHIP and 38:23 K:BB in 43 innings with Syracuse (eight starts, one relief appearance), so he'll likely fill a long-relief role during his time with the big club.
The Mets reassigned Santiago to minor-league camp Saturday, Deesha Thosar of the New York Daily News reports. The left-hander was hoping to win one of the last spots in the Mets' bullpen, but the club elected to keep Rule 5 pick Kyle Dowdy instead. Santiago is set to begin the season at Triple-A Syracuse.
Santiago signed a minor-league deal with an invitation to spring training with the Mets on Saturday, Matt Ehalt of The Bergen Record reports. Santiago spent 2018 with the White Sox, starting seven games and appearing in 42 more in relief. His 4.41 ERA and 22.4 percent strikeout rate are respectable, but he walked 13.0 percent of opposing batters and finished with a 5.09 FIP. His FIP hasn't been below 5.00 since 2015. He'll likely be battling for a long-relief role in New York but could wind up making a handful of starts if things break his way.
Santiago won't start Wednesday against the Indians with Jace Fry scheduled to open for the White Sox in what amounts to a bullpen game, James Fegan of The Athletic reports. Manager Rick Renteria hasn't clarified who will follow Fry in the reliever's first start of 2018, but as one of the few stretched-out options in the bullpen, Santiago is a good candidate to fill multiple innings for the White Sox. Santiago was used in Monday's series opener, but only threw four pitches while retiring two hitters. He'll thus be fairly fresh as he prepares for what will likely be his 49th appearance of the season in the big leagues.