Town, fourth in the Championship before Saturday’s action, are chasing a seventh home win out of nine against the second-bottom Latics.
And Wagner, whose side have lost four of their last six games, wants to make sure the unusual match day makes no difference to his players.
“We are used to Tuesday night games, so this is similar,” he explained.
“The schedule has been altered a little, but it has brought benefits too.
“The longer gap between the game at Cardiff City and that against Wigan has allowed us to carry out some fitness tests.
“We went to the University of Liverpool for these and the result were encouraging and useful.”
Wagner accepts Town need to improve their set-piece defending in the wake of the 3-2 setback at Cardiff City.
“It wasn’t a problem earlier in the season and we are working to stop it being a problem now,” he said.
“It is in the minds of the players.
“They must see a set-piece as a chance to defend, not something to be fearful of.
“The players show confidence and trust in each other in open play.
“They must show it in defending set-pieces as well.