St. Louis Cardinals general manager John Mozeliak is busy working the phones at the MLB trade deadline. So, who is next to go?

The Cardinals have already traded away key players like Jordan Montgomery and Jordan Hicks — both of whom are technically rentals — for five prospects. FanSided's Miranda Remaklus outlined those prospects in a piece earlier this morning, but it's also become clear that Mozeliak is far from done.

Mozeliak even said so himself, telling the St. Louis Post-Dispatch "I don't think we're done."

So, who could be next? One look at the Cardinals roster suggests there are several expandable players who don't fit the 2024 plan for this team. We'll start with the obvious.

STL Cardinals who should be traded next: Jack Flaherty

I mean, come on.

Jack Flaherty has been staring down the barrel since late last week, when he got emotional in what could be his final start in St. Louis. He'd also welcome a reunion come the offseason, but that's neither here nor there.

"I won't lie, I was a little bit distracted. This is probably the first time I've ever been distracted over something that wasn't baseball," Flaherty said, per The Athletic. "It just kind of happened,It was probably the last inning I got, (I wanted) to go out and do what I needed to do and I tried to do a little bit too much. I just got caught up in everything that was going on. I think I've done a good job of taking it for what it is prior to that, but I think in that inning I got a little bit away from myself."

Flaherty is not the ace he once was, but for some lucky contender he could be a mid-rotation starter or even receive a postseason start or two if he succeeds in a new environment.

STL Cardinals who should be traded next: Dylan Carlson

The Cardinals are prioritizing Jordan Walker and Lars Nootbaar in the outfield, as they should. That leaves Dylan Carlson as a likely odd man out. Tyler O'Neill, whose injury history and contract made him a popular trade rumor target for much of the season in St. Louis, is now likely to stay as well.

Carlson has another three years of control left on his contract. The Cardinals should be able to get something of value for him, especially if they pair Flaherty or another pitcher with Carlson. St. Louis hopes to trade for young pitching, while the Seattle Mariners are said to need outfield depth. Could a trade for Logan Gilbert, who the Cardinals have scouted, be on the horizon?

Either way, Carlson's already drawn interest from the Baltimore Orioles, New York Yankees and other borderline contenders. He's not much use in St. Louis unless Mozeliak and Oli Marmol believe he can turn his bat around. Carlson can also play center field, which increases his overall value to outfield-needy teams. He has the sort of flexibility one would want in an OF target.

MLB trade rumors highlighted Carlson's value, but also his recent demise as of the 2023 trade deadline:

"Carlson, unlike the other three players the Cardinals have traded in the past 24 hours, is not a free agent at season's end. He has three years of club control remaining beyond the current season. A former top prospect himself, the 24-year-old's standing in St. Louis has seemingly deteriorated as he's produced at a roughly league-average level since turning in a strong 2021 campaign."

Perhaps some contending team still sees value in Carlson, but for now pairing with him Flaherty or another pitcher is the right decision.

STL Cardinals who should be traded next: Paul DeJong

Paul DeJong is far from the player he once was, but the former NL All-Star still has some trade value left, so expect the Cardinals to deal him. DeJong made the NL All-Star team back in 2019, but hasn't been the same player since. This season, he's slashing just .233/.297/.412 in 81 games. He hasn't received regular playing time and is listed as the backup shortstop behind Tommy Edman (when healthy) and for good reason.

So, will some team try to kick the tires on DeJong? Several already have, as the Cards have received calls from the San Francisco Giants and Boston Red Sox in the last week. San Francisco, for one, has a particular interest in the infield market. As NBC Bay Area points out, there is an urgency to the Giants situation:

"DeJong likely will be traded sooner rather than later. The seven-year vet has posted a .725 OPS with 13 home runs in 297 plate appearances this year. In 2017, he finished second in Rookie of the Year voting after hitting 25 homers.

He has posted a .305 on-base percentage in his big league career, but as Thairo Estrada (hand) and Brandon Crawford (knee) work their way back from their respective injuries and Casey Schmitt's struggles persisting, DeJong certainly could be used in the meantime."

DeJong provides an immediate upgrade for a winning team, and can be had for an affordable asking price. St. Louis could even pair him with Flaherty or Carlson, in this case, should San Francisco be interested in the pitching or outfield markets.