Watford boss Tom Cleverley revealed up to half a dozen players are fasting for Ramadan after his side faded following a bright start in a 2-1 home defeat by Millwall.
The Hornets dominated the opening half with crisp passing and good movement and went ahead through Mattie Pollock's header from a corner.
But the second half saw the visitors hit back with two goals as Watford's play-off aspirations suffered a setback.
Asked about players fasting, Cleverley told BBC Three Counties Radio: "I think we're the most-affected squad in the league when it comes down to that.