Arizona Diamondbacks
The Arizona Diamondbacks are getting some starting pitchers back soon, as Merrill Kelly and Eduardo Rodriguez are throwing simulated games now. This will bolster their starting rotation. The D-Backs can shift their focus to the bullpen with these returns. Despite already adding A.J. Puk, the Diamondbacks could continue to bolster their relief corps.
The Diamondbacks are healthy and stable on the position player side, so they'll look to continue to bolster their pitching groups in both the rotation and the 'pen. The Diamondbacks' general manager, Mike Hazen, stated that he's looking at pitchers with ample team control. The Diamondbacks have plenty of depth on the position player side to trade from, and their farm system is strong, particularly with position players.
The Cardinals are also looking for starting pitching, but if they swing a deal for a player like Erick Fedde, Cal Quantrill, or Yusei Kikuchi, they could trade away one of their starters or starting pitching prospects. Andre Pallante has done quite well as a starter for the Cardinals, and he will likely lose his spot should John Mozeliak trade for a starter. This loss could result in him becoming a trade candidate.
Zack Thompson has been yo-yoed as a starter and a reliever in both the majors and at Triple-A, and players like Gordon Graceffo and Sem Robberse could be trade candidates. If the Cardinals are trading away these prospects with ample team control, they'll look to get more than just a rental in return. Randal Grichuk is a right-handed outfielder who could play center field, something the Cardinals are searching for, but he's just a rental.
If St. Louis trades one of the aforementioned pitchers, Grichuk alone wouldn't cut it. Jake McCarthy is surplus given the glut of outfielders the D-Backs have. McCarthy bats left-handed, but his splits actually favor left-handed pitchers. He could be a sneaky addition should the Cardinals send one of Matthew Liberatore, Andre Pallante, Zack Thompson, Gordon Graceffo, or Sem Robberse to Arizona.