Borussia Dortmund sporting director Sebastian Kehl described reports of poor behaviour from Giovanni Reyna during the United States World Cup campaign as incomprehensible.
Gregg Berhalter s young USA side suffered a last-16 exit against the Netherlands after finishing second in Group B at the tournament, with Reyna playing a limited role.
The attacking midfielder featured for a total of just 51 minutes in Qatar, and reports have since suggested the USA almost sent him home due to a lack of commitment in training.
Reyna labelled such reports highly fictionalised in a social media post on Monday, expressing disappointment that any dispute with Berhalter or his staff had been made public.
The 20-year-old has the backing of his club, with former BVB midfielder Kehl saying any questions over his professionalism are unjust.