When the Vancouver Whitecaps quietly began to shop American center back Tim Parker in the offseason, there was plenty of interest, but also a major obstacle.



Parker was entering the final year of his contract and wanted a new deal that would pay him above the league maximum budget charge—something that can only be accomplished under MLS’s complicated salary rules with a designated player slot, or by utilizing “allocation” funds set aside to manage the salary cap. Multiple teams were willing to deal assets for Parker and meet those demands. The problem, according to multiple sources: The league would not approve a deal for Parker that required Targeted Allocation Money (TAM).



It was the latest example of a league-wide trend as TAM opens a new sector of the transfer market for MLS teams.



MLS took a major step forward when it announced, during the offseason, an increase of $2.8 million in discretionary TAM to add to the $1.2 million in...