Anthony Martial and Fred struck at Old Trafford.
The 27-year-old captained Leicester to last season’s Premiership title under Borthwick’s tutelage.
Paratici was last month hit with a 30-month ban but remained busy during the final days of the transfer window.
Goals from Anthony Martial and Fred secured a comfortable 2-0 win to add to their 3-0 first leg victory to take United into the final against Newcastle