Depending on your definition of “contender” there are approximately 20 teams that are in go-for-it mode as the trade deadline approaches.

Most of these teams are pretty good defensively, particularly the Blue Jays, Rangers, and Brewers, who enter the day as the top teams in Defensive Runs Saved this season.

But there are some who are not stellar on defense, and this article is intended to look at them and see if and where they might wish to upgrade as they chase a playoff spot.

Here are four teams that rank among those with the fewest Defensive Runs Saved this season for whom some aspect of their defense has been an issue in 2023 (rank and Runs Saved in parentheses).

Phillies (24th, -15)

The Phillies have been here before. They ranked 25th in Runs Saved last season and went to the World Series. You might recall that they did add a couple of players who were defensive upgrades in outfielder Brandon Marsh and infielder Edmundo Sosa. And they got an unlikely boost from right fielder Nick Castellanos, who made several great defensive plays in the postseason.

This season, they may have already made their biggest upgrade in calling up center fielder Johan Rojas, who was leading all minor leaguers at that position with 16 Runs Saved at the time of his recall.

Rojas’ presence allows for an outfield of Marsh-Rojas-Castellanos from left to right and takes what is by far their biggest defensive liability, left fielder Kyle Schwarber (-18 Runs Saved!) off the field. When Cristian Pache returns for an elbow injury, he can be the defensive replacement for Castellanos late in games.

What the Phillies need more than trades is for some of their best players to play better defense. Catcher J.T. Realmuto (-3 Runs Saved) and shortstop Trea Turner (-4) have uncharacteristically bad numbers in the field this season.

Red Sox (23rd, -14)

A four-game winning streak and 15 wins in the last 20 games have vaulted a team that looked like it was going to be a seller right back into the AL Wild Card race.

This week is one in which teams do a lot of self-evaluation, and Red Sox insiders have likely come to the realization that they’re a flawed defensive team at multiple positions.

Their best defenders are right fielder Alex Verdugo (11 Runs Saved) and catcher Connor Wong (6).

But center fielder Jarren Duran (-3) and left fielder Masataka Yoshida (-5) rate below average at those positions, as does third baseman Rafael Devers (-5) and first baseman Triston Casas (-5). None of those players are going to be sat for defensive reasons because their bats are too good. When Casas does sit, Justin Turner has been an alright replacement (3 Runs Saved at 1B).

After trading Kiké Hernández, they could make a move in middle infield. Someone like Cardinals shortstop Paul DeJong (11 Runs Saved since 2021) would be an upgrade, whereas the likes of Tigers infielders Zack Short and Andy Ibañez could each fill in at five or six defensive positions.

Marlins (21st, -3)

The Marlins enter Thursday with the fewest Defensive Runs Saved at one position this season. They’re at -19 Runs Saved in center field. That spot likely belongs to Jazz Chisholm Jr. (-6 Runs Saved) when he returns from a strained oblique.

Miami may not have a choice other than to live with this weakness. There aren’t a lot of upgrade options in center field on non-contending teams unless the Cubs move Cody Bellinger or the Padres make Trent Grisham available. There isn’t a great spot to put Chisholm other than center field when he comes back.

One small move that could pay off would be getting a ‘defensive closer’ (a late-inning replacement) like Royals center fielder Kyle Isbel (7 Runs Saved).

Giants (19th, 1)

Similar to the Marlins, the Giants have one big defensive hole. That would be shortstop, where their players have combined for -16 Runs Saved, the worst total in the majors at that position.

Brandon Crawford (-11 Runs Saved) is currently on the injured list. When he returns, he probably enters a platoon with someone, whether it be touted prospect Marco Luciano (-6 Runs Saved in the minor leagues), slumping rookie Casey Schmitt (-3) or an acquisition. DeJong, previously mentioned, could be a very good fit here.

BONUS: And one player worth mentioning …

There are a lot of teams looking to upgrade their pitching staffs at the trade deadline. But teams could improve their pitching by upgrading at catcher.

One catcher who could be a difference maker is Austin Hedges of the Pirates.

Hedges ranks tied for 5th with 8 Defensive Runs Saved there and he’s tied for the MLB lead in our pitch-framing stat (Strike Zone Runs Saved). He has a long track record of success in that area.

Hedges may not be a fit for the teams listed in this article but there are others (the Angels might be the most prominent) for which he’d immediately be a boon to a pitching staff.