PHOENIX -- When the D-backs were in Miami last weekend, Arizona catcher Carson Kelly and then-Miami right-hander Zac Gallen spent some time talking.

The pair had been roommates when they were both playing with Triple-A Memphis in the Cardinals' system.

Another thing that linked them together was that they both had departed the Cardinals via trade for big-name players -- Kelly to Arizona in the Paul Goldschmidt deal and Gallen to the Marlins in the Marcell Ozuna deal.

So as the two talked about making transitions to new teams, Kelly extolled the virtues of the D-backs organization.

Just a few days later, Gallen got the news that he was being traded to the D-backs in exchange for Minor League shortstop Jazz Chisholm.

“I had no idea,” Gallen said of the possibility of being traded. “I’m super excited to go to a team in the playoff hunt, so I’m pumped to be around these guys and I’ve heard nothing but great things about the organization.”

Gallen celebrated his 24th birthday Saturday by reporting to his new team, and while Kelly and former Cardinal Luke Weaver are familiar faces, he asked his new teammates to go easy on him as he got everyone’s name down.

Gallen, who made seven starts with the Marlins and compiled a 2.72 ERA while holding batters to a .191 average, will make his first start for the D-backs on Wednesday night against the Phillies.

Speaking of the rotation

D-backs manager Torey Lovullo has lined up his starters for the Phillies series with Merrill Kelly going Monday night and Mike Leake making his Arizona debut Tuesday, followed by Gallen.

That will give the D-backs a six-man rotation this time through. The club has yet to say whether they will keep it as is for another turn through or go back to the usual five-man alignment.