6 trade deadline ideas for the St. Louis Cardinals

The St. Louis Cardinals continue to sputter in 2023, and as the calendar gets deeper into June, there is a growing realization among fans that the iteration of the team they are seeing is not a mirage: The Cardinals just aren't that good this year.

The idea of the Cardinals being sellers at the trade deadline seemed ludicrous before the season. With an offense piloted by Paul Goldschmidt, Nolan Arenado, and newly acquired catcher Willson Contreras, the Cardinals seemed to be an easy pick to repeat as National League Central champions, even if their starting rotation was a question mark.

Unfortunately, the season has spun off the rails, as the offense hasn't delivered as hoped and the starting pitching has had its expected warts. With the Cardinals at the bottom of the worst division in the National League, there are arguments to make about whether they should sell their assets and try again next year or if they should try to compete in a division where they are still somehow only 8.5 games out of first place.

Dane Aerne-Moore, a former Redbird Rants writer, is firmly on the “sell” train, and he whipped up a few ideas on players the Cardinals could deal and some prospects they could acquire from teams that would make suitable trade partners. I gave my thoughts on these deals as well. Not all of the ideas are full trades; some are merely players on the Cardinals who would fit on certain opposing clubs.

These six trade ideas could help the Cardinals replenish their cupboard and build for the future.

Miles Mikolas and Giovanny Gallegos to the Baltimore Orioles for Coby Mayo and Hudson Haskin

After years of occupying the basement of the high-powered American League East division, the Baltimore Orioles are finally flying high as their prospects mature into major league talent. Currently 38-24 and second in the division, the Orioles possess myriad infield prospects but lack a seasoned starting pitcher. 

Miles Mikolas, who has emerged as the Cardinals' top starter this season, could provide that steady veteran presence after erstwhile ace John Means suffered a health setback that will prolong his stint on the injured list through at least July. In Mikolas’ past five starts, he has an elite 1.64 ERA and only three walks in 33 innings.

Giovanny Gallegos would be an excellent setup man for Orioles closer Felix Bautista. Gallegos and Ryan Helsley have shared the Cardinals' closing duties this season. Gallegos has been one of the most consistent relief pitchers in the major leagues over the past four seasons and would serve well to steady the bridge to Bautista.

Coby Mayo, the headline prospect the Cardinals would receive in the trade, is a power-hitting third baseman who ranks as MLB.com's No. 99 prospect and eighth within the Orioles' deep farm system. There is some concern that Mayo will outgrow the hot corner and be forced to move to first base or the outfield, but if that is the case, the Cardinals could soon have some vacancies at those positions that Mayo might fill next season.

Hudson Haskin is ripping the cover off the ball in the minor leagues. An outfielder, Haskin has ascended three levels this season and is hitting .367 with a 1.024 OPS across those leagues. Now in Triple-A, Haskin is athletic and covers a lot of ground in center field. He could potentially push Dylan Carlson to a corner spot or off the team altogether in 2024.

Personally, I'm not a huge fan of this trade for the Cardinals. The rotation for 2024 is a giant question, and Mikolas is one of the few pitchers who is currently penciled in to be a member of it. Also, with Adam Wainwright retiring after this season, the Cardinals would lose another source of veteran leadership in Mikolas if he were dealt.

Jack Flaherty to the Texas Rangers for Jack Leiter

Jack Flaherty's exceptional performance on June 7 against the Texas Rangers likely won’t go unnoticed by a squad that just lost Jacob deGrom to Tommy John surgery. While Texas' rotation is still very good, Flaherty would give the Rangers another quality arm as they look to extend their lead in the American League West. 

Walks have bitten Flaherty this year; he currently leads the National League in that statistic. But in his past six starts, he has a 2.06 ERA in 35 innings. With his contract up at the end of the season, Flaherty is a strong candidate for the Cardinals to flip, and his value could be on the upswing. 

Jack Leiter is the 76th-ranked prospect on MLB.com. The second overall pick in 2021, he was roughed up a bit last season in Double-A but has found much more success upon repeating the level this season. Leiter has an elite fastball and a good slider, although, like Flaherty, he has had issues with walks. But with a 3.88 ERA so far this season, 69 strikeouts in 51 innings, and an opponent average of .206, Leiter seems to have turned a corner and would be the Cardinals' second-highest-ranked pitching prospect after Tink Hence.

I would love this trade for the Cardinals, but I'm not sure the Rangers would want to pull the trigger on trading Leiter for a pitcher who has only been elite for half of a season in 2019. Given Texas' other four strong rotation pieces, the fact that playoff rotations only warrant four starters and the relative unimportance of needing a full five studs in the rotation, Flaherty might not be enough to satisfy the Rangers.

Paul Goldschmidt to the San Francisco Giants for Kyle Harrison and Carson Whisenhunt

There has been some recent buzz about the possibility of the Cardinals trading star first baseman Paul Goldschmidt, and while that seems farfetched, the Cardinals might entertain some offers for him if the right return is presented. Goldschmidt's contract expires after 2024, and the reigning National League MVP is putting together another strong season, hitting .286 with 10 home runs to this point.

The San Francisco Giants are in third place in the National League West, five games behind the first-place Arizona Diamondbacks. LaMonte Wade Jr. is having a solid year as the Giants' primary first baseman, but Goldschmidt would provide an offensive jolt to the lineup and move Wade to the outfield, where the Giants could use some help.

Kyle Harrison, the Giants' top prospect and No. 15 on MLB.com, has ace-caliber stuff and would give the Cardinals an arm to build around. He has had control issues this season, walking 34 batters in 38 innings in his first exposure to Triple-A. He has struck out 66 batters in that span, though — nearly two per inning.

Carson Whisenhunt, the Giants' eighth-ranked prospect, is also performing well this year. The lefty has a 1.84 ERA in 44 innings and an opposing batting average of .151 through three minor league levels. The Cardinals might fast-track him to the major leagues as a 22-year-old who just pitched his first game in Double-A.

A trade of Goldschmidt would be akin to a Cardinals fire sale, and while I might be too deep into my bottle of Kool-Aid in thinking that the Cardinals shouldn't be sellers yet because the division is so weak and anyone who makes the playoffs has a chance if the Cardinals were to make this move, I would be excited with the return. If Harrison can rein in his walk totals, he could be a frontline starter.