"Our big advantage is all of the players who were away. The players who played in the qualifying games for the World Cup come back in a good mood," Wagner told reporters on Thursday.
"It is a good atmosphere in training and in our dressing room after the games they played. Everybody is healthy and this is very important.
"It is up to us to help them to be part of the teams that will be going to Russia."
Forward Laurent Depoitre and midfielder Danny Williams also played in friendlies for Belgium and the U.S. respectively, and Wagner confirmed that all had returned without injury concerns.
Huddersfield are 10th in the standings and travel to 17th-placed Bournemouth on Saturday.
(Reporting by Aditi Prakash in Bengaluru)
