The 21-year-old has been released by the Championship club after an eight-year association.
Following the end of their 2014-15 campaign, Birmingham have announced that they have parted ways with several players, including the 21-year-old, who was quick to express his gratitude to the Championship club for helping develop him through the initial stages of his career.
Born to an English father and American mother, Packwood joined Birmingham in 2007 after moving from the States to England, before progressing through the club’s ranks to earn his first-team debut in March 2012.
The versatile defender would go on to make five appearances over the first half of the 2012-13 campaign, before suffering a horrific leg break which kept him out for the best part of 10 months.
Particular mention as well to the outstanding medical team who have done so much for me, including helping me recover from my leg break.— William Packwood (@WPackwood) May 5, 2015
The team remained faithful to him during his spell on the sidelines, even offering him a contract extension, but he would struggle to hold down a place in the squad following his return to action.
After spending part of last season on loan at Bristol Rovers, the US Under-23 international featured just once for the Blues this term, taking in further loan spells at Colchester United and Cheltenham Town before his release.
Packwood nevertheless remains a well-regarded prospect within the US setup and even earned a senior call-up in March 2014, when he was an unused substitute for a 2-0 defeat to Ukraine.
The Massachusetts-native is still to make his debut for Jurgen Klinsmann’s side but is in the Under-23 team’s plans for the 2016 Olympics, having featured in recent friendlies against Bosnia and Herzegovina and Denmark.
However, despite his undoubted promise, whether he can keep himself in the international picture will rest on securing regular first-team football at his next destination.
Meanwhile, compatriot Jonathan Spector does not have to fret about finding a new club, having been offered a new two-year contract by Birmingham with an option for a third year.