Travis Shaw, Josh Pennington, Mauricio Dubon, and Yeison Coca for Tyler Thornburg
This trade made perfect sense at the time. Travis Shaw fell short of expectations during the 2016 season and got relegated to a platoon role with Aaron Hill in July. As he continued to struggle down the stretch, he was replaced by Brock Holt and did not start a single postseason game. He would finish the season with a .242 average and 16 home runs.
Pablo Sandoval had disappointed in 2015 and was injured for almost all of 2016. The main complaint was about his work ethic, with reports of him being on Instagram during a game and lack of discipline with his weight. The memory of his belt breaking after a swing remained firmly in everyone’s minds. However, reports of his weight loss and revitalized desire to become the excellent player he once was began to convince people that he was due for a comeback season.
Hanley Ramirez had cemented his role at first base (Shaw’s other position) after hitting 30 home runs with a .286 batting average. There was simply nowhere for Shaw to play.
On the other hand, Tyler Thornburg was coming off a breakout season in which he posted a 2.15 ERA and 2.83 FIP in 67 innings out of the bullpen for the Milwaukee Brewers. He was entering his first year of arbitration and would be under control for three years.
With Koji Uehara and Junichi Tazawa both hitting free agency, the Red Sox needed an elite relief arm to serve as the setup man for Kimbrel.
In December of 2016, the Red Sox sent Shaw, Josh Pennington, Mauricio Dubon, and Yeison Coca (later added to the trade) to the Brewers for Thornburg.
Pennington never reached the majors and retired due to arm issues. Dubon broke into the league in 2019 at the age of 24, but was traded to the Giants and is currently their No. 11 prospect. Yeison Coca was barely above the Mendoza Line in Single-A last year.
On the other hand, Shaw posted two 30-HR seasons with the Brewers in 2017 and 2018, while the Red Sox flailed about trying to find a steady starter at third base. 10 different players tried the position for Boston in 2017, with none of them finding steady success until the call up of Rafael Devers.
Thornburg missed all of 2017 with an arm injury. Health problems and under-performance continued to plague him, and he finished his time in Boston having pitched only 42.4 innings with a 6.54 ERA.
In the end, we can safely say that this was one of the worst trades in recent memory, with the Red Sox giving up a talented contributor while receiving very little production in return.