Rockies leadoff man and outfielder Charlie Blackmon is also nominated for Best Major Leaguer.
• Vote for this season's best stars and moments in the Esurance MLB Awards
The Rockies' manager and a front-office member are also nominated, with Bud Black up for Best Manager and senior vice president and general manager Jeff Bridich in the running for Best Executive. Bridich oversaw a club that reached the postseason for the first time in eight seasons, a run aided by offseason additions such as Greg Holland and Ian Desmond.
Voting led off with seven categories on Sept. 18 at mlb.com/awards, serving as the grand entrance of a program that unveiled nominees for Best Call, TV/Radio; Best Major Leaguer, Postseason; and Best Postseason Moment following the Fall Classic's final out. The ninth inning of voting began around Baseball Writers' Association Awards week, which opened when the Jackie Robinson Rookie of the Year Award winners were unveiled Monday, Nov. 13. Voting in the Best Executive, Best Rookie, Best Manager and Best Pitcher categories went live earlier this week, preceding balloting in the Best Major Leaguer category.
MLB Awards season will culminate Friday when winners are announced live on MLB Network and MLB.com starting at 6 p.m. MT.
Here is a closer look at the Rockies' nominations:
Best Major Leaguer: Arenado put together a lengthy highlight reel at the hot corner, and he also made an impact with his bat, leading the NL with 43 doubles. In addition, Arenado hit .309 with a .959 OPS, 37 home runs, 130 RBIs and 100 runs scored.
Meanwhile, Blackmon led the NL in six offensive categories with a .331 batting average, 137 runs, 213 hits, 14 triples, 387 total bases and 725 plate appearances.
Best Defensive Player: Since his debut in 2013, Arenado has consistently been among baseball's best defenders at the hot corner for the Rockies. He's up against the Red Sox's Mookie Betts, the Twins' Byron Buxton, the Braves' Ender Inciarte and the Angels' Andrelton Simmons.
Best Performance: Arenado punctuated his first career cycle with with a three-run walk-off homer on June 18 against the Giants.
"It's number one," Arenado said of his walk-off homer after the game. "Obviously, it's one of the best moments of my career. Winning the WBC [for Team USA this year] is up there. I've had some big homers, but this by far is the best."
Best Play, Offense: Arenado's Father's Day cycle was also nominated in the Best Play, Offense category.
Best Play, Defense: Among Arenado's many defensive highlights was a remarkable diving stop, spin and toss from his knees to throw out the Giants' Ty Blach on June 28.
Best Manager: In his first season as Rockies manager, Black shepherded a young and inexperienced starting rotation, and he navigated around several injuries to key players like Desmond. In the end, it resulted in Colorado's first postseason berth since 2009.