1. Lucas Giolito
Who could forget the moment when the Los Angeles Angels decided to keep Shohei Ohtani and go for it at the trade deadline, Lucas Giolito was one of the first acquisitions made by the Angels to help enhance their chances at making the playoffs. After all, Giolito had been part of the Chicago White Sox front end of the rotation for the past few years and was having a great year so far in 2023. In 21 starts, Giolito sported a 6-6 record with a 3.79 ERA, 1.22 WHIP, 131 strikeouts in just 121 innings pitched.
However, it has certainly been nothing but chaos once he joined the Angels, as he suddenly became a batting practice machine for opposing hitters. In six starts, Giolito was a horrific 1-5 with a gaudy 6.89 ERA, 1.47 WHIP, giving up 25 earned runs including 10 home runs, 15 walks and 34 strikeouts in just 32.2 innings of work. That was certainly enough to make the Angels raise the white flag recently, essentially ending their playoff run as they waived a whole bunch of their deadline acquisitions to help save money for the future.
More importantly, Giolito has continued to show he was certainly a deadline bust, as when the Cleveland Guardians claimed him off waivers from the Angels, he would subsequently produce a disastrous outing in his first start with the Guardians, giving up nine runs including three homers in just three innings of work. He might have had the pedigree of being one of the more consistent and effective pitchers in all of baseball in recent years, but he has certainly been truly disappointing for his new ballclubs during the stretch run.