Watford boss Walter Mazzarri is unsure what the repercussions of Alan Pardew's sacking by Crystal Palace will be for his own team.
The Hornets have been preparing to face their south east rivals at Vicarage Road on Boxing Day, but the fixture has taken an unexpected twist after Pardew was dismissed in reaction to a run of one win in 11 Premier League matches.
"We cannot know if it will help us. There could be some changes, but it could also be a disadvantage for us," Mazzarri said.
"When this happens I am not happy because, at the end of the day, managers are colleagues, but this is football and it's only the managers who pay the final price.
"I don't know what the dynamics at Crystal Palace are so I can't judge, but I am not happy about this. I didn't expect it, for sure.
"It's points that count, but when I watched Palace play, they played good football and they have very good players."
Defender Sebastian Prodl and striker Stefano Okaka could be fit to take their places on the bench against Palace.
Prodl and Okaka, who are suffering from a dead leg and hamstring injury respectively, have returned to light training and will be monitored over the coming days.
Mazzarri revealed that Roberto Pereyra could be facing an extended spell on the sidelines because of his knee injury.
"With an injury like this there are many variables and many changes that can happen, so it depends on many things. For sure he will be out for some months," Mazzarri said.