The Italian named his starting XI for the game earlier today.
He has revealed that McClean's physical strength as well as his ability has earned him a place in the team.
"He played well [in the reverse fixture]," Trapattoni told reporters.
"He is also physically strong and this game is a tough game. It will be technical, but also a physical game against Sweden. They are strong physically.
"At first, I thought about playing the game with four strikers, but then I thought three strikers is already enough and also during the game, the other options could be important."
Ireland take on Sweden 7.45pm tomorrow.