The Portuguese has enjoyed an excellent first season at Hillsborough.
The former Sporting manager is in his first season in England, but appears to be in with a good chance of leading the Owls to the play-offs in the Championship. And the centre-back explained that one of the key reasons why the squad have done so well is the amount of research that the Portuguese does before each game.
"All I can say is that the preparation for games is fantastic. Each week we have a game plan and I don't think we ever really play the same week to week," he told the Star.
"That's probably one of his the manager's strongest points that we are so well prepared week to week."
The amount of preparation Carvalhal does is surely why he has adopted a rotation policy that has seen only three of his squad make more than 30 starts in the league this term.
As well as monitoring their fitness, the preparation seemingly allows the boss to understand which players would be perfect for each opponent, and it appears to be a plan that is working tremendously.
The Owls are currently fifth in the table with just seven games to go. And considering that they have won their last three games, scoring seven and failing to concede a single goal, it seems that they are well on course to extend their season, and potentially secure promotion.