1. Jacoby Ellsbury: Seven Years, $153 Million, 2013
The GOAT. The absolute, undisputed worst free agent addition in Yankees history (so far), a contract that turned so bleak the Yankees turned to the long arm of the law to resolve it.
In Boston, Ellsbury was a thorn in the Yankees' side and a star of the Red Sox 2007 and 2013 playoff runs, but he wasn't exactly a stable threat. He had a full season lost to injury in 2010 after he collided with a fellow outfielder, and lost a half-year during the Bobby V-helmed campaign in 2012 (but didn't we all?).
Even before he became a Yankee, there was an air of mystery attached to his name -- has anyone figured out why on earth he hit 32 home runs during an MVP-caliber 2011 season, then only topped 10 once during the rest of his career? His full seasons to start his career consisted of 9 bombs, 8 bombs, and a hefty 32, then back down to 9. Would love an earnest explanation.
Everyone agreed Ellsbury was an overpay at the time, but hell, the Yankees could clearly afford it based on the rest of their offseason (McCann, Carlos Beltrán, eventually Masahiro Tanaka). Plus, didn't it feel good to steal from the Red Sox? Ells would steal some bags and hit .270 at worst, though he might go into the void from time to time after bonking heads with a fellow outfield mate.
His first season in the Bronx was on point: those 16 dingers, 39 stolen bases, 111 OPS+. Would've mattered more on a better team. But he never again was a league-average offensive player, peaking at a 97 OPS+ in 2017, his fourth (and final) active year with the Yanks.
From there, he missed two full seasons with oblique issues, back issues, hip problems (and eventual surgery), and foot stuff, then was taken to court in an attempt to void the end of his deal because of a visit to an unapproved doctor. No word on whether it was Dr. Pavano or Rogers.
Eventually, Ellsbury got his money, but that's how petty the Yankees were towards the end of this deal. It's hard to imagine anything souring harder -- and we'd rather not imagine it anyway.