Former Midwest League pitcher Wade Davis signed a three-year, $52 million contract with the Colorado Rockies on Friday, making the All-Star closer the highest-paid (per year) reliever in MLB history.

The deal reportedly includes a $15 million vesting player option for the 2021 season. The guaranteed part of the contract pays Davis $16 million in 2018, $18 million in 2019, and $17 million in 2020.

Davis was a starting pitcher when he made his major-league debut for the Tampa Bay Rays in 2009. The Rays traded him to the Royals in December 2012, and Kansas City traded him to the Chicago Cubs in December 2016.

Since the Royals converted him to a full-time reliever in 2014, Davis has led all MLB relievers with a 1.45 ERA. In 2014-15, he became the first qualifying pitcher in MLB history to record consecutive seasons of 1.00 or less (1.00 in 2014 and 0.94 in 2015). He had a 1.87 ERA in 2016 and a 2.30 ERA in 2017. He has 79 career saves.

Davis was exclusively a starting pitcher when he was in the minor leagues, including the 2006 season with the Midwest League’s Southwest Michigan Devil Rays. (That team moved from Battle Creek to Midland and became the Great Lakes Loons starting with the 2007 season.) He went 7-12 with a 3.02 ERA, 165 strikeouts and 64 walks in 146 innings (27 starts) in the Midwest League. In his final MWL start, Davis pitched a seven-inning no-hitter against the Beloit Snappers — and lost the game 1-0. (That was one of only four times a MWL team has lost a game despite pitching a no-hitter. The Lansing Lugnuts did it most recently, vs. the Peoria Chiefs in the second game of a doubleheader on July 14, 2016.)