Spray medium skillet with nonstick cooking spray. Heat over medium-high heat until hot. Add sausage and potatoes; cook 8 to 10 minutes or until sausage is no longer pink, stirring frequently. Remove from skillet; cover to keep warm.
Reduce heat to medium. Add onions and eggs to same skillet; cook 3 to 5 minutes or until eggs are firm but still moist, stirring frequently. Remove from heat.
Spoon sausage mixture down center of each warm tortilla. Top each with egg mixture. Sprinkle each with cheese. Fold bottom of each tortilla up over filling; roll up. If desired, serve with salsa.