After taking multiple injury hits to their rotation, the Arizona Diamondbacks are glad pitcher Jordan Montgomery came aboard late in free agency.

Montgomery (1-0, 1.50 ERA) won his first start for Arizona over the San Francisco Giants on Friday. He will make his second start Wednesday as the Diamondbacks face the St. Louis Cardinals to close their three-game road series.

The Cardinals won the series opener 5-3 on Monday and the Diamondbacks rolled to a 14-1 victory Tuesday.

Montgomery, who spent the bulk of last season with the Cardinals before his trade to the Texas Rangers, went six innings in his first start for the Diamondbacks. He held the Giants to one run on four hits while striking out three and walking nobody.

"I'm glad I can make a good first impression," Montgomery said after his Arizona debut. "Being around these guys even for three days, they're incredible. They made me feel welcome. So a lot of comfort here and I'm excited to just kind of get deeper relationships with them."

Montgomery struggled in his two preparatory starts for Triple-A Reno, allowing nine earned runs in 7 2/3 innings.

"It is what it is in the minor leagues," Montgomery said. "You go out there and don't really have any competitive juices flowing. Of course, I'm competing, but I'm also trying to throw more fastballs and work on glove-side fastballs and mixing in some sliders ... so it's just totally different. Different sequences, different counts and guys are just swinging sometimes -- you never know."

The Diamondbacks are missing starting pitchers Merrill Kelly (shoulder), Ryne Nelson (elbow) and Eduardo Rodriguez (left lat). So manager Torey Lovullo welcomed Montgomery's arrival.

"I know that he's been aching to be with us," Lovullo said. "All the things that he had to do to get here and probably the nervous energy about having his first start on April 19, he managed it as good as you possibly could have hoped. He was executing pitches, attacking the zone."

Montgomery knows the Cardinals well from his time in St. Louis. But he has never faced them.

In addition to putting Kelly on the injured list on Tuesday, the Diamondbacks also placed relievers Miguel Castro and Kyle Nelson on the list and promoted Tommy Henry, Andrew Saalfrank and Justin Martinez from Triple-A Reno.

The Cardinals will start Kyle Gibson (1-2, 5.04), who delivered a quality start in his last outing, a 2-1, 10-inning loss to the Milwaukee Brewers on Friday. Gibson allowed one run on three hits and four walks over six innings while getting in sync with catcher Willson Contreras.

"He just gets me thinking about the report that we've gone over," Gibson said, "and he's done a really good job of kind of zigging at the right times. And tonight was a couple of those at-bats where I'm thinking along with him, and maybe some of that is learning my lesson from the last (time) shaking him off. But just thinking along with him was a lot of fun."

Gibson suffered a 4-2 loss to the Diamondbacks on April 13 in Phoenix. He allowed four runs on six hits, including Lourdes Gurriel Jr.'s three-run homer, in six innings. He walked three and struck out two.

He is 3-3 with a 2.75 ERA in six career starts against the Diamondbacks.