In a corresponding move Wednesday, the Hurricanes recalled forward Clark Bishop from Charlotte.
The 19-year-old Necas, the team's first-round pick in 2017, was sent down a day after he scored his first NHL goal in a 4-2 loss at Tampa Bay. He was averaging only about 10 minutes of ice time.
The 22-year-old Fleury skated in only one game this season for the Hurricanes and their crowded defensive corps.
Bishop has one goal and two assists in four games with Charlotte.