Sargent was tackled by goalkeeper Lee Nicholls when heading the ball into an open net to give Norwich the lead in the 11th minute, after blocking the keeper's attempted clearance. Nicholls then appeared to land on Sargent's ankle and the striker remained on the ground before being substituted.
"It looks like a serious ankle injury, unfortunately," Norwich coach David Wagner said. "We will assess him tomorrow, and then we will have to wait and see how serious it actually is."
Sargent has scored in Norwich's last three league games, with the team sitting in second place after four matches.
The 24-year-old has scored five goals in 23 games for the U.S. and was named in its squad for the 2022 World Cup, appearing three times.
The U.S. is set to play two friendlies next month, against Uzbekistan in St. Louis on Sept. 9 and versus Oman in St. Paul, Minnesota, three days later. Gregg Berhalter's side will also take on Germany and Ghana in October friendlies.