Philadelphia Union connects to Seattle Sounders FC in 3 degrees through shared players, DP transfer and coaching. First, Philadelphia Union links to Sporting Kansas City via shared players: CJ Sapong played for both Philadelphia Union and Sporting Kansas City Then, Sporting Kansas City links to LA Galaxy via DP transfer: Dejan Joveljić (Designated Player) traded from LA Galaxy to Sporting Kansas City (2025). The first cash-for-player trade in MLS history at $4 million. Finally, LA Galaxy links to Seattle Sounders FC via coaching: Sigi Schmid managed LA Galaxy (1999–2004, 2017–2018) and Seattle Sounders FC (2009–2016).