Enzo Maresca believes Chelsea "need to raise our standards" after their 2-1 defeat to Manchester United.

The Blues were reduced to 10 men after just five minutes after Robert Sanchez's red card, and they were two goals down by half-time.

Another red card, this time for Casemiro, evened up the numbers again for the second half, but Trevor Chalobah's second goal in his last four league games proved to be just a consolation.

Chelsea are winless in their last 13 Premier League away games against United (seven draws, six losses), and against no other side have they ever been on a longer such run on the road in the competition.

Despite Sanchez's early sending off, Maresca was disappointed in his side's performance at Old Trafford.

"It wasn't good enough from us as a club. The first 15 minutes was the worst we have played all season. We struggled in the first half," Maresca told Sky Sports.

"Always difficult going to 10 men down. United were up for it, and they put us under pressure.

"We have played in the Premier League long enough now, so we just have to learn from this and move forward.

"Whether it is 10 men each, it is always difficult from 2-0 down. We need to reflect over not starting well, and we need to raise our standards as a collective."

After Sanchez's red card, Maresca made three changes inside 21 minutes, the earliest a side has ever done so in a Premier League game.

Although he revealed Cole Palmer was substituted due to fitness concerns, the other changes – Filip Jorgensen for Estevao and Tosin Adarabioyo for Pedro Neto – were both tactical.

Maresca told BBC Sport: "They attack with five players, so the idea was to defend with five players. You can defend with four at 11 v 11.

"The game probably changed after they conceded the red card, also with Casemiro. We were much better.

"Cole, this morning, did a test to play this game. He was not 100%. It was a fantastic effort for the club, for his team-mates, for the team. Unfortunately, he was not 100%.

"We need to start the game better. We cannot concede a red card at Old Trafford after three minutes."