Walter Mazzarri has lamented referee Paul Tierney's failure to award Watford at least one penalty in the goalless draw with Swansea City on Saturday.
Both sides had chances to win the game but it was the hosts who ended the stronger at the Liberty Stadium, as the Hornets held out for successive clean sheets.
Watford had two claims for a spot kick turned down by the man in the middle, however - one from a Kyle Naughton challenge on Valon Behrami and another following Naughton's alleged handball.
Speaking after the match, Mazzarri told reporters: "I tend not to comment on referees but I've seen the video and maybe we were unlucky with the decisions.
"So perhaps we could have had three points, but overall I'm happy because we played in a smooth way at times and that's how I'm asking them to play."
Watford, who are now ninth in the Premier League table after a quarter of the season, return to action next weekend with a home match against another struggling side in Hull City.
