I don't think it is.
You can take an educated guess what the injury is from the description. It's safe to assume its not responding to treatment or else he wouldn't be going to the States.
Those two things should be pretty concerning. It's an injury that technically you can play through but he's going to be limited until it heals fully.
This could mess up his entire season even if he does return in two weeks time
Could well be, its concerning that he's going to the US for treatment.
As you said it would be easier if he had surgery and you knew he would be out for x amount of weeks.