It also fills a major hole for them following the news of the team's previously anointed closer, Luke Gregerson, being placed on the 10-day disabled list.
Gregerson, signed in the offseason to an $11 million, two-year contract, saved 31 games for Houston in 2015 and 15 more the next season.
Holland missed the entire 2016 season after undergoing Tommy John surgery and put on an impressive comeback performance during his lone season in Colorado.
Over his career, he's got a 2.60 ERA and 186 saves.
The Mets have tabbed righty Jacob deGrom as their starter. deGrom recorded 239 strikeouts over 201 innings a year ago (with only 59 walks), while finishing the season 15-10 overall with a 3.53 ERA and a 1.19 WHIP. Gurriel was suspended after making an inappropriate gesture during Game 3 of the World Series.
Earlier on Thursday, FanRag Sports' Jon Heyman first reported about the deal being close and then added that it was just about done, pending a physical. But for some reason, no other team would take on chance on the reliever.
This signing carries very little financial risk for the Cardinals with it being only a one-year deal. The Phillies will go with four starters until Arrieta is ready to pitch.
The Rockies will now get the No. 76 pick for compensation for losing the veteran player and the Cardinals will lose their second-round pick in the 2018 draft and $500K of global money. Pitcher Kyle Zimmer, a 2012 first-round draft pick from USF, was designated for assignment by the Royals.