Jose Mourinho was disappointed to learn of a Christmas party which saw Tottenham players Sergio Reguilon, Erik Lamela and Giovani Lo Celso breach coronavirus regulations.
Pictures circulated on social media of the Spurs trio at a festive gathering, with West Ham's Manuel Lanzini also in attendance.
The party went against COVID-19 rules put in place by the UK government as those present ignored social-distancing guidelines.
Head coach Mourinho was particularly disheartened having gifted Reguilon with a cooked pig to help him adjust to his first Christmas in England.
"I gave him an amazing gift, a Portuguese piglet, which is amazing for Portuguese and Spanish," Mourinho said after Tottenham's 3-0 defeat of Leeds United on Saturday.
"I gave him it because I was told he was going to spend Christmas on his own. I had this thought about him. He was not alone, as you can see.
"We as a club feel disappointed. We give the players all the education, we give the players all the conditions and, of course, we are not happy. It was a negative surprise for us."
Reguilon had started Spurs' prior match at Wolves but was an unused substitute against Leeds, while Lamela was absent from the squad. Lo Celso is injured.
Between the games against Wolves and Leeds, Tottenham had a trip to Fulham postponed due to coronavirus cases in the home camp.
Asked if he was angered by the behaviour of his players, Mourinho added: "I prefer to say disappointed.
"We know what we are internally. We don't need to open the door to you and let you know what is going on internally, what are going to be the consequences, how we approached that negative surprise. I feel disappointed, just that."
Lanzini appeared as a substitute in West Ham's 1-0 win at Everton on Friday but apologised for his part in the controversy the following day.
"I want to apologise for a bad mistake I made over Christmas and I take full responsibility for my actions," the midfielder wrote.
"I know people have made difficult sacrifices to stay safe and I should be setting a better example."