MLB Game Preview - San Francisco at Arizona

Wed Apr 5, 2017 9:40 PM EDT

PHOENIX -- The Arizona Diamondbacks say they were excited to acquire Taijuan Walker from Seattle in the offseason.

The Diamondbacks will get their first regular-season look at Walker on Wednesday night when they continue a four-game series with the San Francisco Giants at Chase Field.

The Diamondbacks paid a heavy price to get Walker, dealing second baseman Jean Segura, arguably their best player last season.

Still, Arizona manager Torey Lovullo said he was surprised Walker was available.

"I'm not sure why," Lovullo said. "It's not my department. But when I heard he was part of this organization, I was pretty excited."

Observing Walker while working on the coaching staff for the Boston Red Sox, Lovullo said: "I saw somebody with tremendous mound presence who had command of three pitches, who was aggressive down in the zone with his fastball and was swing-and-miss with his fastball."

He passed this assessment onto new Arizona general manager Mike Hazen. It was part of Hazen's due diligence on the right-hander.

Walker, 24, went 22-22 with a 4.18 ERA in Seattle. He was 11-8 with a 4.56 ERA in 2015 and 8-11 with 4.22 ERA last season.

With the Diamondbacks, he is the No. 3 starter -- counted on to bolster a pitching staff that has flopped in recent seasons and hasn't exactly sparkled in the first two games against the Giants.

That's why the Diamondbacks were willing to part with Segura, whose 203 hits led the National League and were the second-highest mark in franchise history. He also hit .319 with 20 homers and 64 RBIs.

For the Giants, Matt Moore is entering his second season with the team after being acquired at the trade deadline last season from the Rays. The Giants went 7-5 in his starts, as Moore recorded a 4.08 ERA.

Arizona and San Francisco have split their first two games.

Giants closer Mark Melancon blew a lead in the season opener Sunday afternoon and San Francisco dominated the Diamondbacks' pitching Tuesday night in an 8-4 win.

The Giants also got a huge lift from their bench Tuesday, when Gorkys Hernandez was a surprise starter in center field after Denard Span came up with a sore hip. Hernandez responded with a career-high four RBIs.

"I've said this so many times: The bench plays such an important role during a season," Giants manager Bruce Bochy said. "Those guys, when they come through for you and deliver for you, it makes it easier to rest guys. When something like this happens, a guy shows up and can't go, then you put a guy in there that softens the blow of losing your regular."

Hernandez didn't know he was going to start until he showed up at the ballpark and saw his name on the lineup card. Then he went to work in the batting cage.

Arizona first baseman Paul Goldschmidt homered Tuesday and needs one more hit for 848 in his career; that would move him past Steve Finley for No. 2 on the team's hit list. The career leader is Luis Gonzalez, who had 1,337.