March 14 (Reuters) - Manchester United ( MANU ) manager Ruben Amorim described Bruno Fernandes as the "perfect" captain on Thursday after his hat-trick sealed a 4-1 Europa League win over Real Sociedad but said the midfielder must also show some trust in his teammates.

After a 1-1 draw in the first leg in Spain, United fell behind at Old Trafford to Mikel Oyarzabal's penalty before Fernandes scored three goals, twice from the spot, to put the hosts in the driver's seat.

Fellow Portuguese international Diogo Dalot added a fourth in stoppage time to seal a 5-2 win on aggregate and send United into the quarter-finals.

"When we need it, (Fernandes) is always there," Amorim said. "He can bring the ball forward. He can score goals. He is a perfect captain for our team and we need to help him win titles."

However, Amorim noted Fernandes was sometimes guilty of disrupting United's shape by drifting out of position in search of the ball.

"We know that sometimes he is frustrated," Amorim added. "We know he wants to win so badly and when things are not going well, he is changing position and going after the ball.

"Sometimes he needs to trust his teammates."

United visit Leicester City in the Premier League on Sunday.