Philadelphia Union acquire Kai Wagner from Birmingham City | OneFootball

By Jonathan Sigal

TRANSFER TRACKER STATUS: Signing

The Philadelphia Union have acquired left back Kai Wagner from EFL Championship side Birmingham City, the club announced Friday.

The German defender is under contract through the 2028-29 season with an option for 2029-30. He will occupy a Designated Player roster spot.

Wagner returns to Philly seven-plus months after being transferred to Birmingham City. He previously spent seven seasons with the Union (2019-25).

To complete the transaction and claim Wagner off waivers, Philadelphia acquired the top spot in the waiver order and $100,000 in 2026 General Allocation Money from Sporting Kansas City in exchange for a 2026 international roster spot and the 22nd position in the waiver order.

"We’re thrilled to welcome Kai back to Philadelphia. He’s been an integral part of this club’s success and has consistently established himself as one of the top left backs in Major League Soccer," said Jon Scheer, Philadelphia sporting director.

"Kai understands what this club represents, what our supporters expect, and the standards we hold ourselves to every day. We’re confident he’ll make an immediate impact this season as we pursue our goals and be an important part of our club's future."

During his first stint in Philly, Wagner tallied 10g/54a in 253 matches across all competitions.

He helped them win the 2020 and 2025 MLS Supporters' Shields and was named a three-time MLS All-Star and two-time MLS Best XI honoree.

At Birmingham City, Wagner provided 1g/3a in 18 games for the English second-division team. 

"Coming back to Philadelphia feels incredibly meaningful for me and my family. Over the years, this city has become our home, and returning was a decision that came from the heart," said Wagner.

"My time away gave me the opportunity to experience a new challenge, but it also reinforced how much this club, this city, and our supporters mean to me. There’s something special about representing the Union and playing in front of our fans. I believe in what this club stands for, its culture, ambition, and commitment to competing at the highest level.

"I’m excited to be back and grateful for the opportunity to help write the next chapter."

The Union return from the FIFA World Cup break on July 22 vs. Red Bull New York (7:30 pm ET | Apple TV).

Ryan Richter is acting as interim head coach after the club parted ways with Bradley Carnell in late May.

READ MORE: MLS Transfer Tracker