Fitness levels may have played a part in Watford's late defeat to Chelsea yesterday, defender Craig Cathcart has admitted.

The Northern Irishman and his team mates had kept Antonio Conte's talented side to half-chances for the majority of the Hornets' first home league match under new boss Walter Mazzarri, but two strikes inside the final 10 minutes saw all three points slip away from their grasp.

A change in formation helped the Blues ramp up the pressure on their hosts and dominate the final 20 minutes, and two defensive lapses helped them clutch victory from the jaws of defeat.

Cathcart was left frustrated Watford had not got more from the game - but conceded Chelsea's superior fitness may have proved the difference in the end.

He said: "Fitness might come into it a little bit, but it’s still early in the season and we’re all finding our feet.

"The games come thick and fast so over the next few weeks I’m sure it won’t be a factor at all.

"We want to mix it with the best teams and we did today. It’s hard to look at the positives because we feel so deflated losing those two late goals. 

"But we’ll look at the game in the next few days and look at the positives and pick ourselves up."

Part of Cathcart's frustration, he said, came from a sense of injustice over the result; unfancied by many, the Hornets had been the better team for most of the opening 70 minutes.

The 27-year-old was particularly impressed with the hosts' first-half performance, and felt they had at least done enough to continue their unbeaten start.

He said: "I think we deserved at least a draw. I thought we were excellent in the first-half, and restricted them to very little.

"We got in behind a few times and in the second half we knew they would come at us and knew they had a lot of quality."