St. Louis Cardinals: Is a Kelvin Herrera-Kolten Wong swap possible?

ST. LOUIS, MO - JUNE 11: Kolten Wong #16 of the St. Louis Cardinals fields a ground ball against the San Diego Padres in the ninth inning at Busch Stadium on June 11, 2018 in St. Louis, Missouri. (Photo by Dilip Vishwanat/Getty Images)
ST. LOUIS, MO - JUNE 11: Kolten Wong #16 of the St. Louis Cardinals fields a ground ball against the San Diego Padres in the ninth inning at Busch Stadium on June 11, 2018 in St. Louis, Missouri. (Photo by Dilip Vishwanat/Getty Images) /

With the St. Louis Cardinals bullpen continuing to frustrate, it was only a matter of time before trade rumors about relief pitcher began to swirl around. One such rumor revolves around the Royals’ reported interest in Kolten Wong, and a possible swap for reliever Kelvin Herrera.

The time may have arrived for the St. Louis Cardinals to find a new home for Kolten Wong. Additionally, the Cardinals need bullpen help.

Kelvin Herrera is the heir to All-Star closer Wade Davis in Kansas City, and has been a solid late inning reliever for a large majority of his eight seasons in the league. If you subtract his rookie season in which he only played two games, Herrera has a 23-26 record with a 2.70 ERA, 1.31 WHIP, and 438 strikeouts in 439.1 innings.

Kolten Wong has had an up and down career with the St. Louis Cardinals, and this season has certainly been a down period. He’s still hitting below the Mendoza line this season at .182, but he has stayed in the lineup with great defense. He is tops in the league among second baseman in Defensive Runs Saved, a measurement used to quantify how many runs a player saved or lost a team as a fielder.

He rates well in other defensive metrics as well, so it’s not as clear cut and dry as looking at the basic numbers. Here are a few factors that would effect the Cardinals’ decision to swap Wong for Herrera, and my thoughts on how they compare.


Wong: 27 (October 10, 1990)

Herrera: 28 (December 31, 1989)

Before all else, this is the first thing that teams will consider when making a trade. As you can tell by the less than year’s worth of age difference, it isn’t too big of a deal here.

Herrera played his first full season when he was 21 while Wong did so at 22, but the difference in the amount of wear and tear is a single season at most, which is not nearly enough difference to impact a deal. They have also both been quite durable, though Wong has been taken out due to more nagging injuries then Wong has.

Wong has a small age advantage, while Herrera has the slightly cleaner bill of health. It’s a matter of preference really.

Verdict: Push

Recent Performance

Wong: 1.8 WAR in 2017, 0.9 WAR in 2018

Herrera: 0.2 WAR in 2017, 1.2 WAR in 2018

Wong and Herrera have both had similar stories over the last year, just the chronology of it is reversed. Herrera struggled mightily in 2017 to the tune of a 4.25 ERA and 1.35 WHIP, while we as St. Louis Cardinals fans are bearing witness to Wong’s struggles this season offensively, but his defense has been elite, keeping his WAR at an attractive level.

According to Fangraphs, Wong is one of the top defensive second basemen in the league this season. Here are some of the stats:

Wong FieldingWong’s Rank among 2B
Defensive Runs Saved1st
Plus-Minus Runs Saved1st
Ultimate Zone Rating/150 games1st
Range Runs Saved1st
Ultimate Zone Rating2nd
Double Play Range7th

For a team that has had its struggles defensively both in the infield and outfield, Wong has been a stabilizing force in the infield. While Jedd Gyorko has been another serviceable defender, Wong has been beyond serviceable: he has been arguably the best defensive second baseman in the majors all season.

While Herrera didn’t have that positive side to 2017, he has been stellar in 2018. He has only allowed three runs for a team that is at the bottom of the AL with an obscene 5.5 runs allowed per game, and is toward the bottom in defensive efficiency. Herrera has been the lone bright spot in a tough season for Royals pitching, stranding 98.9% of batters on base while he pitched.

It’s a close one as seen by the WAR’s, but Wong has actually been an important piece for the St. Louis Cardinals in 2018 while racking up over 100 hits and hitting .285 in 2017. While the hitting has been inconsistent, Herrera’s 2017 was simply a bad year.

Verdict: Wong

Career Performance

Wong: .250/.320/.372, 36 HR, 178 RBI, 54 SB, 8.3 WAR in 584 G

Herrera: 23-27, 2.75 ERA, 1.13 WHIP, 438 K, 57 SV, 10.0 WAR in 442 G

Wong’s numbers aren’t quite so flattering here, while Herrera’s still look like a tier 2 reliever who is close to being among the best based on his career numbers.

This is mainly due to career consistency. While Wong has performed better over the past two seasons, he has been rather inconsistent throughout his career, as the offensive fluctuation shows. He has alternated years hitting above and below .250 from the moment he stepped in the league, and that is where is career number currently sits.

More from St Louis Cardinals Rumors

While he shows the makings of a great hitter during his highs, he can’t seem to sustain them, and has trouble getting out of slumps. So you could say Wong is consistently inconsistent.

Herrera on the other hand has been quite the opposite. He is proving with each inning of work in 2018 that last season was just an anomaly, and it’s not hard to believe it. Before 2017, he had only finished one season above a 3.00 ERA, and has a 2.96 FIP from 2012-2016.

While Wong’s defensive prowess cannot be understated, the consistency of Herrera compared to the roller coaster ride of Wong makes this an easier choice than it may seem at first.

Verdict: Herrera

Contract after 2018

Wong: 3 years, $29,250,000, $12,500,000 Team Option in 2021

Herrera: UFA in 2019

This is a tricky one because the preference once again can vary based on not only what part of the building process a team is at, but the age and potential of the prospects themselves. The Cardinals are a team who, despite the gradual decline in recent seasons, are still a team that is trying to win.

However, based on what we have seen with this season, the Cardinals don’t just need a single piece to propel them over the top. It is going to take some time to climb back into championship contention, so the Cardinals want players that they will have control over for several seasons.

Herrera doesn’t fit that bill, with a contract that’s expiring this season, so it would be on the Cardinals to make a decision on whether or not they can either convince Herrera to sign an extension or win a title this season with this and other moves.

Just like with the Manny Machado situation, the contact situation becomes the most important point of interest. It certainly isn’t ideal, and it’s much safer to just keep Wong on this front.

Verdict: Wong

Should the Cardinals look for a Wong-Herrera Swap?

Herrera is a great player and Wong’s troubles at the plate have made him an attractive option in Cardinal trade rumors, but there are a few obstacles. The main one is the same one that makes it difficult for the Cardinals to trade for Machado.

Quite frankly, the Cardinals need more than just a reliever to compete with the Astros, Red Sox, and other elite teams. That being said, the Cardinals can certainly make more trades on top of this one to put themselves in a good position to win a title this year. Herrera makes just a million dollars more than Wong this season, so the trade wouldn’t cause any cap casualties.

There’s another problem though, and that’s the risk that comes with going all in and falling short. Chances are that Herrera will explore his free agent options in 2018, and it will be tough to convince him not to, especially if he continues this performance.

If it is part of a grand scheme that has a legitimate chance of making noise, then the front office should go for it. I have doubts that that is even possible without mortgaging the foreseeable future, and the Cardinals have never been a team to undergo roster overhauls, so making this trade on it’s own seems too risky.

Verdict: NO

Next: Want more rumors?

Do you think Herrera would be a key addition to a playoff run? Is Wong’s defense expendable? Do you want to see this trade happen? Leave your thoughts in the comments below.