"We just think there have been a lot of things going in a good direction [for Gonzales]," said Matheny. "I think he's ready ... he deserves an opportunity."
Gonzales, 22, was the Cardinals' top pick in the 2013 First-Year Player Draft out of Gonzaga, and he played for Rocky Mountain High School in Fort Collins. His father, Frank, is the pitching coach for the Rockies' short-season Class A affiliate, Tri-City.
Matheny stressed the Cardinals decision came down to Gonzales being "the guy who can help us win," not his familiarity with the mile-high air. Still, he did admit the latter gives Gonzales an edge over some of his peers he leapfrogged.
"You start thinking, 'OK, if there's a kid from Florida who hears about Coors Field [he] might be a little more hesitant coming in not knowing what to expect," said Matheny. "I don't think there's that as much for a kid [where] this is what they grew up in."
Gonzales started his season in Class A Advanced Palm Beach, registering a 1.43 ERA in 37 2/3 innings, before being promoted to Double-A. In seven starts with Springfield, he struck out 46 against 33 hits and 10 walks in 38 2/3 innings.
"He's the kind of pitcher I used to love to catch," said Matheny. "[Gonzales] is a guy who can handle real, small, incremental adjustments on the plate. [He has] a real nice changeup and can get a lot of ground balls and a lot of early outs."
Gonzales is expected to join St. Louis on Tuesday. The Cardinals will have to clear room for him on their 40-man and 25-man rosters.
Cody Ulm is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.