Guerra, a 30-year-old who once upon a time was a headliner in the 2008 Johan Santana trade that sent the left-handed ace from Minnesota to New York, has never quite found his footing in a 14-year professional career thus far. A 2012 move to the bullpen was precipitated by severe bat-missing issues, a malaise that transmuted into homer and command problems in relief stints with both the Pirates and Angels from 2015-17.
He has been sharp this year, however, with 10.45 K/9 against 2.18 walks per nine in 41 1/3 treacherous innings in the homer-happy PCL. Numbers like those will allow him to linger in the upper minors for as long as he chooses, though the far-below average fastball (per MLB standards) may keep him knocking on the big-league door for some time.
Smith, 29, is a former well-regarded Padres and Rays prospect who ran into a heavy wall with Kansas City last season. Injuries kept him out of both the 2015 and ’16 seasons, and the low-slot Smith hasn’t since been able to regain his long-ago form. In 13 starts for San Antonio this season, Smith has paired a strong strikeout rate (10.24 K/9) with sloppy command. He’ll likely be deployed in relief with Milwaukee, though the team’s current pitching mix needs help wherever it can get it.