Source: Mike Axisa, CBS Sports 
Despite a strong showing in camp (3.38 ERA and 5.67 K/BB in 21 1/3 innings), Tigers left-hander Drew Smyly was squeezed out of the rotation in a numbers game, losing the spot to incumbent fifth starter Rick Porcello.
Instead of sending the 24-year old Smyly to Triple-A Toledo, the Tigers kept him around in the bullpen, and their reward: the best left-handed reliever in baseball (by FanGraphs WAR) in 2013.
In 76 innings spread across 63 appearances, Smyly pitched to a 2.37 ERA (178 ERA+) with a 1.04 WHIP and a 4.76 K/BB ratio… that’s 81 strikeouts against only 17 walks.
He clearly has the stuff to be a starter even though his changeup is still a work in progress, plus, from his point of view, it’s far more lucrative than pitching in relief.
For now, Smyly has to settle for being a key cog in the Tigers bullpen and being one of the best relievers in baseball, righty or lefty.