Duke, 33, is pitching well in the second season of a three-year, $15MM contract signed with the White Sox prior to the 2015 campaign. He currently leads the American League with 53 relief appearances, though he’s clearly been deployed in a largely specialized role, as he’s totaled just 37 2/3 innings in those 53 contests. Duke has posted a 2.63 ERA with 10.0 K/9 against 3.8 BB/9 and a 58.8 percent ground-ball rate. While Duke has been used in left-on-left matchups with great frequency, he’s held right-handed opponents in check this season (albeit with the help of a .238 BABIP). He’ll give the Cardinals some needed bullpen depth and join Tyler Lyons and Kevin Siegrist as a third left-handed option for manager Mike Matheny.
Duke is earning $5MM this season — of which about $1.78MM remains — and is owed $5.5MM for the 2017 season as well. Cardinals fans may recall Duke from his days with the Pirates, but he reinvented himself as a reliever with the Brewers in 2014 and parlayed a brilliant season with Milwaukee into his current contract. Since that 2014 breakout, Duke has a 2.87 ERA with 10.4 K/9, 3.7 BB/9 and a 57.2 percent ground-ball rate.
Tilson, meanwhile, ranked 10th among Cardinals prospects on Baseball America’s midseason update of the organization’s top prospects and 12th on MLB.com’s version of the Cards’ top 30. BA writes that he has some of the best speed in the organization and strong contact skills but bottom-of-the-scale power. MLB.com agrees, noting that he’s selective at the plate, can bunt for hits and is capable of hitting to all fields but lacks pop. Tilson has the speed and range to play center field, and both reports indicate that he can be at least a fourth outfielder in the Majors, if not an everyday player whose game is geared toward speed, contact and defense.