Quique Sanchez Flores was left upset at the nature of 10-man Watford's 2-1 defeat against Tottenham at Vicarage Road, but refused to criticise referee Anthony Taylor's decision to send Nathan Ake off.
Ake was dismissed in the 63rd minute after he sent opening goalscorer Erik Lamela to ground with a high foot, and the hosts were punished with one minute of normal time remaining when Son Heung-min snatched the victory despite claims of offside.
Flores was frustrated Watford's five-game unbeaten streak came to an end in such a manner, but praised the effort of his team.
"I feel sorry because we had possibility to draw and it was painful to how we lost the match," he said.
"But I am really proud of my players. They fight a lot, have an amazing soul, they always play at the best level."
On Ake's red card, the Watford head coach said: "I had an amazing view but I do not like to criticise the performance of the referees.
"It's football. Sometimes it happens for our team, sometimes for the other team."