Jeff Passan of Yahoo Sports provided further information about Oakland's return for its former ace:
Following three excellent seasons to start his MLB career, Gray struggled mightily in 2016 to the tune of a 5-11 record with a 5.69 ERA, 1.50 WHIP and 94 strikeouts in 117 innings.
The 27-year-old righty then began the 2017 season on the DL with a back injury, and he has posted a 3.43 ERA and 1.18 WHIP with 94 strikeouts in 97 innings across 16 starts since returning to action.
His nightmarish 2016 campaign was a far cry from a 2015 season that saw him go 14-7 with a 2.73 ERA, 1.08 WHIP and 169 strikeouts en route to finishing third in American League Cy Young Award voting.
Big things were expected out of Gray in 2016 after a three-year stretch where he went 33-20 with a 2.88 ERA, but his struggles were a microcosm of an A's team that went a disappointing 69-93 and finished last in the AL West.
Gray is under team control and arbitration eligible for two more years, which was seemingly a good fit for the A's, but they decided to go even younger.
Oakland is in the midst of another rebuild. While Gray is coming off the worst season of his career, the A's landed a solid return in exchange for the former All-Star.
The Athletics went against conventional wisdom by selling low on Gray, but it could turn out to be a savvy move if he is unable to regain the form he displayed in his first three seasons.
New York is banking on the idea that injuries rather than true regression contributed to Gray's struggles in 2016. If that turns out to be the case, they scored a massive coup by landing a quality starter in his prime.
The Yankees have a deep, dangerous lineup and a strong bullpen, but their starting rotation has been a question mark all season long.
Adding Gray goes a long way toward easing concerns, as he and Luis Severino should form a dynamic combination at the top of their pitching staff.
There is still uncertainty elsewhere in the rotation, but the Yanks are now a more dangerous team and bigger threat to do damage in October.