What happened: The selection moves Sullivan from youth-prospect status into the senior U.S. pool ahead of Thursday's full roster release. He had already emerged as one of the expected names for this window after a strong run in league play.
Why it matters: A senior nod this early accelerates his timeline and raises the stakes around his form in the closing stretch of the MLS regular season. He entered the week with 14 goal contributions this season, a return that helps explain why the jump arrived now.
By the numbers: Sullivan is 16 years old and had 14 goal contributions this season entering the week, with recent scoring form helping drive the move into the senior pool.
What to watch: Thursday's official roster release is the next checkpoint. After that, attention shifts to whether this is a one-window reward or the start of a regular senior role.