#5 - Greg Holland: 1 year, $14 million, 2018
I remember being at the early season contest against the Milwaukee Brewers where Greg Holland made his Cardinal debut. He was signed a few days after Opening Day and got some quick work in the minor before joining the Cardinal bullpen. Unfortunately, his debut was exactly how the rest of his time with St. Louis played out.
In 25 innings for St. Louis, Holland had a 7.92 ERA with 22 walks and 34 hits allowed. He was unplayable, and so the Cardinals had to take the hit on the $14 million that they handed out to him. Just an awful move, even for a one-year deal.
To rub salt into the wound, he went on to throw 21.1 innings with the Nationals later that year, posting a 0.84 ERA in the process.