With April in the books, this is a great time to examine what's happened early on in the National League West and look ahead at each club's player to watch in May.

With the Dodgers soaring, the Padres and D-backs off to great starts, and the Rockies and Giants hoping for turnarounds, here are some players who will be key figures this month.

D-backs: Christian Walker

Walker has been a journeyman first baseman, but with Jake Lamb out with a quad injury, he had a breakout April at the plate. By the end of the month, Walker led Arizona with a .994 OPS and seven homers, virtually replacing the offense lost with Paul Goldschmidt's departure.

Walker is a big reason the D-backs had a 17-13 record to open the season, but will his offensive production continue? If it does, Lamb may be headed back to third base upon his return from the injured list, and Arizona may continue its surprising start in 2019.

Dodgers: Walker Buehler

The Dodgers are flying high after posting a 20-12 record through April, led by Cody Bellinger’s tremendous start at the plate. But on the mound, the club's presumed future ace struggled to a 5.22 ERA to open the season after playing a huge role down the stretch last year for the NL champs.

Buehler dazzled with his electric fastball and devastating slider in 2018, shutting down the Rockies in the Dodgers’ division-clinching Game 163 victory last October before tossing 11 2/3 brilliant innings between NL Championship Series Game 7 and Game 3 of the World Series. But another month like April, and concerns will begin to mount in Los Angeles.

Giants: Buster Posey

The Giants found themselves tied with the Rockies for last in the Majors with a 66 wRC+ at the end of April. Outside of Brandon Belt, San Francisco's lineup has been stagnant, in desperate need of a jump-start.

The team had high hopes for an offensive resurgence from Posey after offseason hip surgery. So far, that hasn't materialized, with Posey posting a .707 OPS and one homer heading into May. He's as close to a captain as you can get without a "C" on his chest, and he'll need to lead the Giants out of the doldrums at the plate.

His walk-off single to beat the Dodgers on Wednesday was a good start.

Padres: Chris Paddack

The Padres entered the 2019 season as an exciting club to follow after their big acquisition of Manny Machado, the debut of Fernando Tatis Jr. and the emergence of powerful young outfielders. But the big question mark was the starting rotation.

Paddack was dominant in his first month in the Majors, boasting a 1.91 ERA over six starts. He certainly performed like an ace, and a trusted ace would go a long way toward building a rotation to complement an exciting lineup as the Padres look to contend in the years to come. But one month does not make an ace, making May beyond critical for the right-hander.

Rockies: Daniel Murphy

Signing Murphy was Colorado's response to the loss of DJ LeMahieu and an offense that has chronically underwhelmed over the past couple of years. He fractured his left index finger during the second game of the season, but since returning to the lineup, he has been hot, hitting .304 (7-for-23) with three doubles and two homers in six games to close out April.

A lineup that calls Coors Field home will need to improve significantly for the Rockies to reach the postseason for a third straight year. Putting Murphy in the middle of a batting order with Nolan Arenado and Trevor Story looks great on paper, but Murphy is the linchpin, and the Rockies will hope his meticulous approach to hitting spreads in the clubhouse.