clock menu more-arrow no yes mobile

Filed under:

Who Should Play Third Base for the Diamondbacks?

Based on results in August and September, my choice is a platoon of Emmanuel Rivera and Sergio Alcantara

Emmanuel Rivera plays great defense at third base.
Emmanuel Rivera plays great defense at third base.
Photo by Chase Agnello-Dean/Getty Images

For years third base was not a strength.

After four seasons with Jake Lamb as the Diamondbacks’ primary third baseman, and after three seasons with Eduardo Escobar as the Diamondback’ primary third baseman, this season was a transition, with the Diamondbacks giving playing time to several candidates to be the next primary third baseman.

The bar was set low for the Diamondbacks to improve at third base. For six consecutive seasons (seven if you include this season), third base defense has not been a strength for the Diamondbacks. The following table shows that Diamondbacks’ team defense at third base ranked below average in five of the six previous seasons, and average in one season (2019).

Diamondback team DRS at Third Base. Data from The Fielding Bible and Baseball Reference.

In 2021, third base was played by eight Diamondbacks (4 with at least 50 PAs). The results were below average.

  • Defense. Negative 6 Defensive Runs Saved (DRS) ranked 22nd in the Majors.
  • Offense. 1.6 Wins Above Replacement (WAR) ranked 18th in the Majors (hat tip to Jack Sommers).
  • Overall negative 0.8 Wins Above Average (WAA) ranked 21st in the Majors.

After the 2021 season, my concern for third base was demonstrated when I wrote these AZ Snake Pit articles:

Candidates for Third Base, Candidates for Third Base Another Look, Third Base Three Nominations, Third Base Platoon of Ellis and Rojas, Third Basemen in the NL West, Ryan McMahon or Manny Machado, Poll Results Ryan Mahon or Manny Machado, and Third Base Options to Start the Season.

This season what happened at third base?

In 2022 through 10 September, third base was played by ten Diamondbacks. Three with at least 50 PAs while playing third base were: Josh Rojas 343 PAs, Emmanuel Rivera 83 PAs, and Sergio Alcantara 66 PAs).

The Diamondbacks lost Sergio Alcantara to waivers on 9 May and got him back on 5 July. After he was re-acquired, his OPS steadily improved. His monthly OPS shows a great trend:

  • July: .799 OPS
  • August: .820 OPS
  • September through the 10th: 1.250 OPS

On 1 August the Diamondbacks acquired Emmanuel Rivera in trade for Luke Weaver. Rivera is under team control through 2027. This AZ Snake Pit article suggested he would continue to improve.

“Emmanuel Rivera is a right-handed batter who crushes left-handed pitching (especially in July). The Diamondbacks need him to balance their left-handed batters (Rojas, Thomas, Varsho, McCarthy, Smith, and Beer).” —Makakilo

“Second, ignoring months with very little playing time, Emmanuel Rivera has only four months experience in the Majors. Almost certainly, he is still making adjustments.” — Makakilo

“I love the ability [of Emmanuel Rivera] to make plays defensively; he’s moving laterally very well.” — Torey Lovullo

These three third baseman have great potential to make the Diamondbacks’ third base a strength, especially compared to previous seasons. Which one is best?

Who should play third base?

The following table compares the three third basemen. It showed the following:

  • In August/September Emmanuel Rivera’s defense was outstanding, which contrasted greatly to the average or below defense by the other two players.
  • In August/September Sergio Alcantara’s wOBA and OPS were outstanding. That compared well to Rivera’s excellent offense and Rojas’ near average offense.
  • Before his 5 game hitting streak, Emmanuel Rivera’s wOBA and OPS were by far the best. Including that streak, which ended on 11 September, bumped him to second best, although still better than the Diamondbacks’ averages.
Data from Baseball Savant.

Let’s look at player splits against left-handed pitchers and right-handed pitchers to see if a platoon would yield positive results. The following table shows that based on batting in August and September a platoon of Rivera against left-handed pitchers and Alcantara against right-handed pitchers could provide an outstanding overall OPS.

Data from Baseball Savant.

Although at 26 years old, Emmanuel Rivera and Sergio Alcantara are likely a couple years away from reaching their peaks, the Diamondbacks have many position players who have more room for growth (with 11 position players who have played this season who are younger). Mitigating this concern is that Alcantara does not reach arbitration until 2024, and Rivera does not reach arbitration until 2025. Therefore, the Diamondbacks should focus on performance in deciding who should play at third base.


For the Diamondbacks, third base has not been a strength since 2015. In August/September of 2022, three third basemen demonstrated their skills: Emmanuel Rivers, Sergio Alcantara, and Josh Rojas.

Emmanuel Rivera crushed left-handed pitching, which is very much needed by the Diamondbacks. He demonstrated by far the best defense at third base. He has great potential to improve (very little playing time in the Majors and relatively young at age 26). He would be my choice for primary third baseman, but there is a better possibility.

Sergio Alcantara’s batting has trended upward. In September he crushed right-handed pitchers. Because of their batting splits, a platoon of Emmanuel Rivera and Sergio Alcantara is my choice to play third base next season.