SAN FRANCISCO -- Trevor Story and Brandon Belt, candidates for the final spot on the National League All-Star team, will go head-to-head one last time before fan balloting ends when the Colorado Rockies and San Francisco Giants conclude a three-game series Wednesday night.

The Rockies and Giants split the first two games of the series, San Francisco getting a home run from All-Star catcher Buster Posey in a 3-1 win Monday night before Colorado used a three-run homer from one of its All-Stars, third baseman Nolan Arenado, to erase a deficit and even the series with a 7-3 triumph Tuesday.

Story and Belt were selected to compete against Arizona Diamondbacks third baseman Jake Lamb, Milwaukee Brewers outfielder Ryan Braun and Pittsburgh Pirates outfielder Starling Marte in the fan vote that will determine who joins the NL team for next week's midseason classic in San Diego.

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Balloting ends Friday.

Two members of the Rockies -- Arenado and outfielder Carlos Gonzalez -- and three Giants -- Posey and pitchers Madison Bumgarner and Johnny Cueto -- were among the 34 selected to the NL All-Star team via fan balloting, player votes and manager choices announced Tuesday.

Story didn't get the nod Tuesday in a stacked field of NL shortstops. Addison Russell of Chicago Cubs was voted the starter by the fans, while Corey Seager of the Los Angeles Dodgers was the top choice of the players, making him the backup.

NL manager Terry Collins opted not to take a third shortstop even though he had qualified candidates, including the Giants' Brandon Crawford, who leads NL shortstops with 53 RBIs.

Story, despite being robbed of a bases-loaded double or triple by a spectacular sliding catch by Giants right fielder Mac Williamson on Tuesday night, ranks second to Crawford in RBIs among NL shortstops with 50. He leads NL shortstops in home runs with 19, just missing a 20th with a drive to the center field fence in Tuesday's win.

Story went 0-for-5 in the hard-luck game, seeing his average drop to .259.

The rookie made an immediate name for himself when he began the season with six home runs in his first four games.

He will attempt improve on his gaudy numbers Wednesday when he faces Cueto, who is a candidate to start the All-Star Game. The first-year Giant has won nine games in a row, improving his overall record to 12-1 with a 2.57 ERA.

Cueto's last two starts have been rocky, however, as he allowed a combined 10 runs on 15 hits in 13 innings.

The Rockies will counter with left-hander Jorge De La Rosa, who will take to the mound with him a 5.98 ERA, second-worst among NL pitchers with nine or more starts this season.

De La Rosa (5-5) won four consecutive starts before pitching well in a road loss to the Los Angeles Dodgers on Friday, when he gave up two runs in seven innings.

Belt enters the series finale coming off a two-hit game that raised his season average to .297. Pushing his average over .300 during the balloting period could help his fan appeal.

Despite leading all first basemen in doubles with 26, Belt was passed over in the selection of Anthony Rizzo of the Cubs in the fan balloting, Paul Goldschmidt of the Diamondbacks in the player vote and Wil Myers of the San Diego Padres as one of the manager's selections.

Story will get one additional opportunity to impress the voters when the Rockies begin a four-game home series against the Philadelphia Phillies on Thursday. The Giants have the day off.