Slice the chicken sausage in half lengthwise and grill on the panini press for 4 minutes, or until cooked.
Remove the sausage and then assemble the sandwich by placing the slice of Brie on one side of the bread and topping it with the cooked sausage.
Top with the tomato and arugula then the second piece of bread.
Place the sandwich on the heated panini for 3 minutes until the Brie is softened.
Slice and serve warm.