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He was rewarded for his decision Thursday with a franchise-record contract.
Santana's contract reportedly includes an option for a fifth year that vests if he throws 200 innings in 2018, pushing the potential total sum to $68 million over five seasons.
The signing will cost the Twins their second-round draft pick, after Santana declined a $15.3-million qualifying offer from the Braves last month. Minnesota's first-rounder is protected.
Santana signed with the Braves last winter for $14.1 million after he was unable to secure a lucrative multi-year deal on the open market. He declined a three-year contract from the Twins worth a reported $33 million over three years.
What a difference a year makes.
Santana has put together solid back-to-back seasons after his disastrous 2012, averaging 207 innings and 30-plus starts over his last five years. The 31-year-old struck out 179 batters to 63 walks over 196 innings in 2014. He'll join a rotation that features Phil Hughes in pitcher-friendly Target Field.
Despite allowing the second-most home runs in the majors since 2010, Santana has cut down his fly-ball rate significantly the last two years to below league average. His improved results have been in part attributed to a reliance on his secondary offerings, which he's appeared to lean more heavily on since his successful 2013 season with the Kansas City Royals.