Antonio Valencia says sorry for display in Man United's FA Cup loss to Arsenal.

Antonio Valencia battles with Alexis Sanchez for the ball.

Antonio Valencia has issued an apology to his Manchester United teammates and their fans after his errors helped condemn them to defeat against Arsenal in the FA Cup.

The Ecuador international winger took to Instagram to say sorry after he was at least partly culpable for both goals in the Gunners' 2-1 victory at Old Trafford on Monday.

Right-back Valencia came infield in a failed attempt to stop Alex Oxlade-Chamberlain and left Nacho Monreal unmarked to score Arsenal's opener.

And his under-hit back-pass was intercepted by former United striker Danny Welbeck when he scored the winner to end hopes Louis van Gaal would bring silverware to Old Trafford in his first season at the club.

While manager Van Gaal subsequently described Valencia as "the best man of my team," the former Wigan player was contrite.

"I want to apologise to my teammates and the fans of Manchester United," Valencia wrote on Instagram. "Tomorrow is another day and keep working."

Valencia mentioned United colleagues Marcos Rojo, Juan Mata, Ander Herrera, Rafael da Silva and Robin van Persie in the message, although only Rojo and Herrera actually played in the Arsenal game.

Rafael, who is a rival to Valencia for the right-back spot, then stepped up his case for a place in the team by scoring for United's under-21s against Tottenham on Tuesday.

Source: ESPN FC