Before Kwang Hyun Kim made his first appearance for the Cardinals way back in Spring Training, he admitted he was nervous. He said the same thing before his first regular-season start.

He never pitched like he was nervous.

From the moment he first appeared in a Cards uniform this year, Kim has impressed in every way. With his deceptive slider and fast tempo, Kim won his coaches, manager and teammates over with the way he easily fit in this season. The way Kim returned to the rotation after a kidney scare sent him to the hospital earlier this month -- seven scoreless innings against the Brewers just 10 days after the hospitalization -- further made his mark.

“I’m really impressed with what kind of a winner and competitor he is,” Matt Carpenter said. “You can’t say enough about the pace he pitches with, his ability to throw strikes, get his defense to play behind him -- he’s a lot of fun to play with.”

All of it has led to this: Kim will start Game 1 of the Cards' National League Wild Card Series against the Padres on Wednesday at 4 p.m. CT, live on ESPN2. He found out he was starting after the Cardinals took their celebratory team photo Sunday when they clinched a postseason berth.

“From then on, and until now, I am nervous,” Kim said Tuesday through interpreter Craig Choi. “But I have to do my job. … I’m just going to be bright and just be lively in the postseason.”

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Nerves aside, Kim is ready. The 32-year-old lefty will bring a 1.42 regular-season ERA to face the mighty Padres in the opener of the best-of-three series. Cards manager Mike Shildt said that there were two reasons why Kim got the start over Adam Wainwright (who will start Game 2) and Jack Flaherty (who, if needed, will start Game 3). One was that he’s “earned it,” and the other had to do with Kim having five days’ rest.

Starting Game 1 of a postseason series can have its pressure-filled moments for someone as new as Kim, but Kim isn’t an ordinary rookie. These moments are why he signed with the Cardinals on Dec. 17. Plus, he has 12 years of experience in the Korean Baseball Organization, winning a regular-season MVP and four Korean Series championships in the process.

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“[Some] of the feedback [on] him I got last offseason, which was all very positive and accurate … that [he’s a] really talented guy,” Shildt said. “But he really stepped up into the competition and has been a really good performer in postseason play.”

Kim has pitched at Petco Park once before -- in the 2009 World Baseball Classic. But he’s never faced the Padres. San Diego finished tied for second in the NL with 27 home runs against lefties this season and has as well-balanced an offense as any, with Fernando Tatis Jr., who led the club with 17 home runs; Manny Machado, who slugged .580 this season; and veteran Wil Myers, who had a .959 OPS.

Kim has leaned on his four-seam fastball and slider the most this season, but the way he changes speeds is what keeps hitters off balance. His slider can veer anywhere from 88 to 75 mph. He drops high-60 mph curveballs in regularly. Some of his changeups come in 78-79 mph.

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Cardinals utility man Tommy Edman once called it an “uncomfortable at-bat” to face Kim during live batting practice.

“He does a great job of going after guys,” Edman said Tuesday. “He doesn’t mess around too much. He comes in with a variety of pitches, and that’s what you want in a Game 1 starter. Someone who’s not going to mess around, not be afraid of hitters we’re going to be facing. San Diego’s got a good lineup, but we trust KK to go out there and do what he’s done all year. He’s proven to be able to adapt to a lot of different circumstances. That’s going to serve him well in this first game.”

And Kim has mostly limited damage, with only three home runs -- and only seven earned runs total over 39 innings. That’s what he hopes to continue to do on Wednesday. Kim sought out advice from D-backs pitcher Merrill Kelly, who was Kim’s teammate on the SK Wyverns in Korea for four years, and Korean lefty Hyun Jin Ryu, who faced the Padres many times while on the Dodgers.

“Compared to Korean hitters, the U.S. hitters, they are much stronger,” Kim said. “A lot of sluggers. I try to not pitch a mistake pitch. In the postseason, each run, one run, is really important. You don’t get many runs in the postseason."