Watford defeat was a huge setback for Arsenal - Petr Cech
Petr Cech admits Arsenal were handed a "huge setback" ahead of their crunch meeting with Chelsea at the weekend as Watford left the Emirates Stadium with all three points on Tuesday night.
The Gunners were shocked as their visitors raced into a two-goal lead courtesy of Younes Kaboul and Troy Deeney.
Alex Iwobi hit back for Arsenal at the start of the second half but Arsene Wenger's men could not find another goal to share the spoils and instead the 2-1 defeat now leaves them nine points behind Premier League leaders Chelsea.
A tough trip to face Antonio Conte's Blues is next up, with a defeat at Stamford Bridge not only meaning Arsenal would be 12 points adrift of the summit but also with the possibility of being outside of the top four.
Cech, who won four league titles during his time at Chelsea, was beaten twice in the opening 13 minutes as the Hornets sprung a surprise on Tuesday - and conceded the defeat was all that Arsenal deserved.
"This was a huge setback because this was the game we wanted to win," he told Arsenal Player.
"We wanted to put ourselves in a better position going into the weekend. I always say that at this level you cannot play 80 minutes, or 85. You have to play 90 minutes with full concentration and everybody on top of their game.
"We were second best in the first half. We made so many bad passes, we lost every challenge, we were simply second best, as I said.
"In the second half we improved, we had a lot of chances. I thought we were brilliant second half, but obviously we only scored one goal."
Arsenal were roundly jeered by the home fans at the end of both halves, with some chants of "Wenger out" also recorded as supporters made their way out of the stadium.
Cech insists the players were prepared for the test after Wenger - who watched from the stands as his four-match touchline ban continued - questioned whether his players were "mentally ready" for the challenge posed by Watford.
"We had a very bad start," the Czech Republic goalkeeper added.
"We were unlucky with the first goal when it takes a big deflection and it goes in. Obviously it gave a lot of hope and motivation to Watford's side because this was something that lifted them up.
"But then I think we didn't play well at all. It was too much for us to take in the first half and it's very hard to say why because we were prepared.
"We were on back-to-back wins, important wins, we had the momentum after the Burnley game and obviously the Southampton game went completely our way, exactly the way we wanted."
Wenger will also be sweating on the fitness of Aaron Ramsey, who was forced off with a calf injury early on in the contest, with Granit Xhaka's suspension set to leave the Frenchman short in the midfield area for the test at Chelsea.
For Watford, this was a first win in seven league games and relieved some pressure growing on manager Walter Mazzarri.
And Kaboul, whose deflected drive had given the Hornets the lead, believes the visitors were too hot for Arsenal to handle.
"In the first half they couldn't live with us," he said.
"We were on top of everything from Troy (Deeney) to Heurelho Gomes - all of us were brilliant. We did a terrific job and it will give us a lot of confidence for the rest of the season.
"Everyone on the pitch and the players who came on did a terrific job. The staff got us ready two days after the bad performance at Millwall - I'm very pleased with that.
"We couldn't have started better. We could have scored more, we knew they would come back stronger and they did."