In a very interesting blockbuster swap the Braves have traded outfielder Jason Heyward and reliever Jordan Walden to the Cardinals in exchange for starter Shelby Miller and starter prospect Tyrell Jenkins.
Heyward will be eligible for free agency next offseason, so St. Louis is giving up a combined decade of team control over the 24-year-old Miller and 22-year-old Jenkins for one season of Heyward and the possibility of draft pick compensation if he signs elsewhere.
Heyward hasn’t quite lived up to the hype offensively after posting an .850 OPS as a 20-year-old rookie in 2010, batting .258 with a .762 OPS in four seasons since then. However, his defense grades out as truly elite in various advanced metrics and when combined with good but not great offense makes him one of the best all-around outfielders in baseball. In fact, during the past three seasons the only outfielders with more Wins Above Replacement than Heyward are Mike Trout, Andrew McCutchen, Carlos Gomez, and Alex Gordon.
And the Cardinals paid a big price to get him. Miller is a former elite prospect with a 3.33 ERA in 370 career innings through age 23, although his strikeout rate and control have been underwhelming. He certainly has top-of-the-rotation upside and is under team control through 2018. Jenkins was a first-round draft pick in 2010 and bounced back from season-ending shoulder surgery in 2013 to pitch well in 13 starts at high Single-A this season, although he struck out just 41 batters in 74 innings.
Walden, who goes to St. Louis along with Heyward, should step into a setup role for the Cardinals after posting a 3.10 ERA with 254 strikeouts in 212 career innings for the Braves and Angels. His inclusion in this deal will likely be mostly overlooked, but Walden has shutdown potential in the late innings and throws very hard.