After the Owls lost 1-0 to Boro earlier tonight, head coach Carvalhal confirmed Wednesday contacted the governing body asking for the fixture to be switched to tomorrow to give them more preparation time.
Middlesbrough had nine days to prepare for the televised encounter after their Boxing Day trip to Blackburn Rovers was called off due to a waterlogged pitch.
In stark contrast, the Owls played twice in the space of 72 hours and Carvalhal claimed that extended Christmas break gave Boro a big advantage.
The Football League knocked back Wednesday’s request and Cristhian Stuani’s strike after 44 seconds condemned Carvalhal’s side to their fifth defeat on the road this season as Boro racked up a seventh successive clean sheet, equalling a club record.
Carvalhal, who made six changes to his starting line-up, said: “We asked the League to change the game to tomorrow because there are games then. We asked if it could be moved but the answer was no.
“These kind of things are not good for the competition. This shouldn’t happen. For the competition to be serious, all the teams must play in the same conditions.
“One team shouldn’t play with two days. Three days is the minimum and another team has a week to prepare for.
“We played two days ago, 48 hours ago we played a hard game. Some players must repeat the game as we have some problems with injuries, some are too tired to play.
“If you play with your friends and you also played (48 hours earlier) and your friends didn’t, you will feel a difference on your body. It’s a massive difference - not a small difference - a massive difference.
“I’m sure if it was the opposite and Middlesbrough had played on Saturday, we would win this game.”
Carvalhal said he was “proud” of their spirited second-half display after seeing Boro dominate the opening 45 minutes.
“I’m very happy with the players, especially with what they did in the second half,” he said. “I think we deserved more. We fought until the last minute and we did well in the second half.
“Joe Wildsmith didn’t have much to do but we didn’t trouble their keeper. That is the reality. We had two or three chances to score.
“I am disappointed with the score but I am happy with the players’ performance.”
Sam Hutchinson will be assessed by the Owls’ medical team after being forced off at half-time with an injury.
Daniel Pudil and Gary Hooper are expected to be passed fit for Saturday’s clash at Fulham