A stoppage-time winner from Korey Smith secured the Championship side’s place in the semi-final, sending the reigning champions crashing out of the competition as they lost for a second time in four games.
The Spaniard, who was an unused sub during the game at Ashton Gate, admits it was a huge disappointment for the club but says they must move on if they are going to be successful for the remainder of the season.
“When you play for a club like Manchester United every defeat is a massive blow for everyone,” said Mata.
“For the fans, for you but especially for us. We suffer when we don’t win because there’s such a high standard in this football club to try and win every game.
“But we need to understand that defeat is part of sport and part of football and it can happen so it’s not a tragedy.
“It’s not good at all, but we need to move on and accept it as a part of football and keep moving.
“Obvously we would like to win every single game and we would like to try to do so until the end of the season.”
United’s 3-2 triumph against Southampton to secure the League Cup was a highlight for the Reds last season, but Mata insists there is plenty to fight for as they continue to battle for the Premier League, FA Cup and Champions League.
“It was a competition that we won in February, it was a good way to face the start of the season lifting that trophy at Wembley,” he added.
“We haven’t been able to do it this season but we need to move on and we have other competitions to play for.
“Hopefully we can still go to Wembley in the FA Cup, we are playing in the Champions League where we play Seville and there’s still many games to go.”
Jose Mourinho’s side travel to the King Power Stadium on Saturday to play Claude Puel’s Leicester, as they look to get back to winning ways.
