With Nolan Arenado probably out, who will be the Cardinals' next third baseman?

Nolan Arenado's time as a St. Louis Cardinal is running short. He's been mentioned in several trade rumors, and he's likely going to be moved this offseason.

Should he be traded, he would be leaving a Gold-Glove, All-Star-sized hole at the hot corner, and that spot will be filled with an internal candidate. Several players have a strong case to play third base. Nolan Gorman, Brendan Donovan, and even Thomas Saggese could receive an extended run at third. Who should see the most time there?

It stands to reason that Donovan and Gorman are the headliners for third base, and whoever is left out will play second base primarily. Both Gorman and Donovan are left-handed hitters, so a platoon isn't an option. This decision comes down to defense: who should play the more supreme defensive position at third: Nolan Gorman or Brendan Donovan?

Gorman came up in the Cardinals' system as a third baseman. He transitioned to second base, a spot where he has logged nearly 2,000 innings in his young career after the Cardinals acquired the aforementioned Nolan Arenado in February of 2021. Donovan, on the other hand, has been a utility guy for his entire career, and the bulk of his innings in the majors have come in left field and second base.

At second base, Nolan Gorman has struggled defensively. In 1,999.2 innings at second, Gorman has been worth -20 Outs Above Average (OAA), -11 Defensive Runs Saved (DRS), and he has a -8.3 Ultimate Zone Rating (UZR).

Brendan Donovan, in about half as many innings (947.2 innings) at second, has been more valuable defensively. He's been worth two OAA, -3 DRS, and he has a -1.5 UZR. Neither Gorman nor Donovan are exceptional defenders at second, but at least Donovan can float there.

Nolan Gorman has had more success at third base, albeit in a much smaller sample size. Gorman is a neutral defender at third according to both OAA and DRS, and he has a -0.8 UZR there. Donovan's best defensive position up to this point in his career has been third base. He's accumulated three OAA, seven DRS, and his 3.6 UZR at the hot corner surpasses Gorman by a fair margin.

The other argument here is related to arm strength. Donovan's arm ranked in the 52nd percentile last year, and his throws from third have touched 85 miles per hour. Arenado averaged 84.2 MPH last year. The drop-off would be negligible if there ever were one. Meanwhile, Gorman's arm strength was in the 14th percentile. Throws from third typically grade out faster than second base, but it shouldn't be expected to see a 6-7 MPH difference should Gorman move to be the team's primary third baseman next year.

If the Cardinals and Oli Marmol wanted their best defensive look on the infield, placing Donovan at third base and Gorman at second base may be ideal. There's also credence to the idea that Gorman wants consistency on one side of the game while he figures out the other side.

He's going on his fourth major league season at second base; 2025 is pivotal for his offensive development. By staying at a position he's familiar with at this point, he can focus less on defensive work and more on fixing his swing -- yes, I do know he's a negative defender at second base still.

If both players are slated to receive as many plate appearances as possible next year, it doesn't matter much where they play defensively from an offensive perspective. Gorman will likely mash baseballs while striking out a lot, and Brendan Donovan will pester opposing pitchers while slapping doubles all over the field. Where they play defensively shouldn't change the offensive game plan of either player.

The wrinkle in this story would be if prospect Thomas Saggese shows out in spring training. He's played across the infield as a minor leaguer, and he could overtake Gorman on the depth chart. This isn't the most probable situation, but there's an outside chance Saggese leapfrogs Nolan Gorman to become an everyday starter right out the gate in 2025.

I think it's important to note here that Derrick Goold made it quite clear that Gorman is the club's preference at third. In one of his recent chats, Goold said, "Nolan Gorman will be the third baseman. That is the Cardinals' plan, though they are not going to say so publicly while discussing trades involving Nolan Arenado. Gorman is the plan at third."

The Cardinals' defense will take a hit next year with both Paul Goldschmidt and Nolan Arenado off the roster. It's imperative Oli Marmol fields a roster that makes up for those shortcomings, and playing Brendan Donovan at third and Nolan Gorman at second would help in those efforts. Third base is a more premium defensive spot than second base, and the focus should be placing the team's best defender there. Brendan Donovan is that man for the Cardinals in 2025.