Looking back on the St. Louis Cardinals’ trade for Paul Goldschmidt

The St. Louis Cardinals have traded away promising players to fill holes on the major league roster. How have they fared on other rosters?

We’re going to kill two birds with one stone – or cover two young players with one post, to go with a less violent descriptor – and evaluate the post-trade careers of Luke Weaver and Carson Kelly, the two biggest players the St. Louis Cardinals sent to the Diamondbacks in December of 2018 for Paul Goldschmidt.

Acquiring a six-time All-Star who had earned four Silver Slugger awards and three Gold Gloves, along with receiving MVP votes (including three top-three finishes) in five seasons is a very good thing, especially when he still is in his prime.  Goldschmidt hasn’t been an All-Star with the Cardinals, but has received MVP support in each of his three years in St. Louis, and was awarded one of the team’s five Gold Gloves for the 2021 campaign.

St. Louis has Goldschmidt signed for three more seasons, and if he’s close to the player he’s been so far in his career, the team will be thrilled to reap the benefits of his skills. But the Redbirds did surrender three players and a competitive balance pick to get him, and we need to see how those players have done during their time in Arizona.

We’ll quickly notd that Andrew Young, another player involved in the trade, has played in 70 games for the D’backs the last two seasons, batting .205/.319/.462 with seven home runs.  A breakout is always possible, but a player with those stats who turns 28 in May isn’t someone anyone should count on for such an improvement.

Let’s move on to Weaver, who shifted from St. Louis to Phoenix following his most extensive campaign with the Cardinals.  In 2018, he made 30 appearances, including 25 starts, and threw 136-1/3 innings for the Redbirds.  Unfortunately, he posted a 4.95 ERA (78 ERA+) that year, surrendering 150 hits with his worst strikeout and walk rates in any season before or after.

That 2018 innings total is more than double what Weaver has managed in any other season.  That was understandable in the 60-game 2020 campaign, when he made a dozen starts and threw 52 innings, though with a horrid 6.58 ERA (69 ERA+).  In the years before and after that one, however, extended injured list stays limited Weaver to 64-1/3 innings in 2019 and 65-2/3 frames in 2021.

During that abbreviated ’19 season, Weaver put up a career-best 2.94 ERA (152 ERA+), striking out 69 batters and allowing only 55 hits and 14 walks over those 64-1/3 innings.  And last year was nearly the definition of mediocrity, a 4.25 ERA (101 ERA+).

That’s a large amount of variability and a small numbers of innings, leading to a career ERA of 4.64 and ERA+ of 90 over 415 frames.  The 28-year-old Weaver still has time to blossom, but he needs an improved combination of health and performance to help the Diamondbacks and their fans feel better about the trade that brought him to Arizona.

The other significant player in this deal, Kelly, was the heir apparent to Yadier Molina in St. Louis, but Molina’s continued strong performance made Kelly expendable, and with first base an issue for the Cards, including him in the trade to the D’backs to acquire Goldschmidt was a reasonable call.

Kelly’s performance in Arizona has somewhat paralleled Weaver’s, with a poor 2020 campaign bookended by solid seasons.  In 2019, a .245/.348/.478 triple-slash line with 18 homers in 111 games were a promising start in the desert for the then-24-year-old Kelly.  Things fell apart during the COVI9-20 shortened season, evidenced by a .221/.264/.385 line with just five long balls.

The 2021 campaigned started out very strongly for Kelly, as he hit .340/.507/.717 in April with six home runs.  However, a toe fracture in May shut him down for 10 days, and a wrist fracture in late June sent him to the IL for 40 days.  After that hot April start, Kelly hit only seven more home runs, finishing with a .240/.343/.411 line that worked out to just four percent above average in terms of OPS+.

A catcher who is entering his age-27 season with a batting line just nine percent below average is solid, especially with a similar hope for health and development as the Diamondbacks are looking for from Weaver.  But so far, there’s been more promise and less production from these battery mates.

Would there be roster space in St. Louis for Weaver and Kelly?  Quite possibly.  But when the tradeoff yields a top-tier performer like Goldschmidt, this is a deal the Cardinals would make over and over again.