While the Arizona Diamondbacks have been busy signing free-agent pitchers, they just let one go who was once a huge prospect.

While the Diamondbacks now have Merrill Kelly back in their rotation, they still need to decided whether or not to trade Ketel Marte.

In the first round of the Triple-A phase, the Athletics ended up selecting Abel Mercedes from the Houston Astros. In the second round of the Triple-A phase, the A's added a similar pitcher in Darlin Pinales, a 23-year-old right-hander that had been in the Arizona Diamondbacks system.

After signing right-hander Michael Soroka to a one-year, $7.5 million deal, the Arizona Diamondbacks are still in need of rotation help.

Here is what the Diamondbacks are reportedly looking for in a trade that includes star Ketel Marte, who's been in a bevy of rumors.

While Lowe has had his name mentioned a lot, he isn't the only veteran on the team who makes sense as a trade candidate. Kiley McDaniel and Jeff Passan recently wrote about Rays slugger Yandy Diaz as a potential fit for the Arizona Diamondbacks in a trade this winter.