Gonzalez earned it by pitching 3 1/3 scoreless innings on Sept. 1, a contest started by then-fifth starter Dana Eveland, who gave up five runs in 2 2/3 innings.
Over the previous seven starts by former fifth starters Eveland, Yusmeiro Petit and Byung-Hyun Kim -- who has since been released -- the club's fifth-starter ERA stands at an ugly mark of 12.52.
Gonzalez threw 49 pitches in the outing last week and has not pitched since, but Melvin said he will have no direct pitch count. With a bullpen full of September callups, the club will likely be covered if Gonzalez has a short outing.
Gonzalez has had mixed results pitching in San Francisco this year, giving up one run over seven innings on April 21 but getting shelled for six runs (four earned) in three innings of relief on July 1.
"That'll be good," said catcher Miguel Montero of Gonzalez getting the start. "He's a pretty good pitcher. I'm pretty sure he's going to do good."
With All-Star second baseman Orlando Hudson scheduled to undergo season-ending thumb surgery on Monday, the club has three second basemen on the roster to replace him.
Melvin said Alberto Callaspo would likely be the everyday second baseman once he recovers from a right hamstring injury, which the manager expects to be Sunday. The team also could give time to utility player Augie Ojeda, who has received the last two starts at second, and September callup Emilio Bonifacio.
"He's one of our leaders, he's an All-Star, he's having a great year," Ojeda said of Hudson. "We've just got to pick it up somehow and find a way to pick up the slack and try to win some games without him."
Ojeda has been valuable for the D-backs as a strong defensive player who can capably man second base, shortstop and third. Melvin said he would have no reservations giving playing time to Ojeda, a move team leader Eric Byrnes would not oppose.
"Augie's a good player," Byrnes said. "I think people who have been around the league a while that have seen Augie play know that, but he just hasn't really gotten a ton of opportunities. He's always kind of been that extra infielder, but Augie is very capable. I've always liked him as a player, and we're going to miss 'O,' but we've got some guys that are very capable."
Ever modest, Hudson felt the team would not skip a beat without him. But replacing him might be easier said than done considering he hit .294 with 10 homers and 63 RBIs to go with his typical Gold Glove defense.
"Either way, the team will keep going. They're playing great," he said. "I don't think by me missing a few weeks that these guys are going to miss me, because they're doing a hell of a job. It wasn't like I was swinging the bat that well anyway. They're doing a great job; they're going to be just fine."
Move over Melvin:
Despite the disappointing news, Hudson joked that he would be doing a bit of managing, sitting next to Melvin to help him send the signals in when the club returns from next week's road trip.
"We'll have to find another seat for him is what we're going to have to do," Melvin joked. "What he brings to us in a non-production part, his spirit and everything in the dugout and on the field will still be there, and we need it."
Montero in the five hole:
When Melvin batted Montero fifth on Wednesday, the rookie catcher responded with a two-homer night.
So Montero found himself back in the five spot in his start on Saturday.
"I'm used to, in my career, hitting in the middle of the order," Montero said. "I was feeling comfortable. I feel good; I mean I feel good anywhere I play. Any time I see runners on base I just try to do my job, bring them in."
Enrique Gonzalez gone:
The D-backs designated right-handed pitcher Enrique Gonzalez for assignment when they signed Bob Wickman on Friday.
Gonzalez went 8-10 with a 5.15 ERA at Triple-A Tucson this year. He gave up four runs (three earned) in his only action with the D-backs, a two-inning stint on June 18.
The D-backs conclude their three-game series with the Cardinals on Sunday afternoon at 1:40 MST, with Doug Davis (13-11, 3.98 ERA) squaring off against Brad Thompson (6-5, 5.07) at Chase Field.