The St. Louis Cardinals and Seattle Mariners are not frequent trade partners, but they did swing a trade in 2017 that brought both teams reliable major league talent to their roster.
Tyler O'Neill has been involved in one trade in his career, and the same can be said for former Cardinals lefty Marco Gonzalez. They were dealt for each other on July 21, 2017, in what turned out to be an even trade for both organizations.
Gonzalez played in three partial seasons for the Cardinals before being dealt to the Mariners. He made just seven starts as a Cardinal and did not overwhelm anyone with his big-league ability. He finished his brief St. Louis career with a 4-2 record with a 5.53 ERA, it just did not work in St. Louis, but he went on to rebound in Seattle and has turned into a solid major league pitcher for a playoff contender.
Gonzalez would find immediate success with Seattle in his first full season with the new team. Finally healthy, Gonzalez made 29 starts for the Mariners and amassed a record of 13-9, and would eclipse the 200-inning total in his next season.
In six seasons with the Mariners, the former first-round pick has made 138 starts with a 57-46 record, a 4.00 ERA, and has netted 597 strikeouts in 843 innings of work. He was never fully healthy as a Cardinal, but his production could have been used at times over the last few seasons.
O'Neill, on the other hand, was an unproven commodity as well as he had yet to make an appearance at an MLB game when he was traded to the Cardinals in July of 2017. O'Neill would make his major league debut in 2018 and play in 61 games for the Redbirds. He finished his first taste of the big leagues with nine home runs and 23 RBIs.
Through his first three seasons as a Cardinal, the talent O'Neill had was never in question. Similar to his status entering the 2023 season, the biggest question mark was whether or not he could stay healthy. In 2021, he was finally able to put together a complete season, and major league baseball was finally able to see why the Cardinals traded a former first-round pick for the five-tool outfielder. He played in a career-high 138 games in 2021 and finished eighth in the MVP voting in the National League that season. He hit 34 home runs, knocked in 84 runs, and finished the season hitting .286. He was a threat in every element of the game.
Since that historic season, he has reverted back to his previous form because of his multiple injuries. He played in 96 games in 2022 and is now in contention to take over the everyday centerfield job along with Dylan Carlson and Lars Nootbaar.
With both players having played at least five seasons with their new teams, it seems like it was a very even trade. Both players have been borderline all-star caliber performers, but they have had issues staying on the field.