Adu was originally reported as the Union's newest signing by Soccer By Ives and Fox Soccer. There still hasn't been any official word on whether or not the former child prodigy will be the Union's first ever designated player, but the team did note in its press release that Adu is a free transfer from his former team, Portuguese powerhouse Benfica.
Chivas USA was the destination that the American soccer community believed would be acquiring Adu, but the team's owner stepped in at the last possible minute and canceled the deal. He apparently wants more Mexicans on the Southern California team.
The 22-year-old will be the Union's second ever allocation order acquisition. After taking Adu through the United States Men's National Team re-entry process, the Union move back to the end of the list. That means that either a trade with a team higher up, or every team bringing in a USMNT player will put them into position to add another through allocation.