Antonio Conte side-stepped questions on David Luiz's future and made light of speculation over his position after once again proving the scourge of Jose Mourinho at Stamford Bridge.
Alvaro Morata's second-half header earned Premier League champions Chelsea a 1-0 victory over Manchester United which ensured they remain nine points behind leaders Manchester City, who second-placed United now trail by eight points.
It was Mourinho's third loss in three visits to his old stomping ground with United and came after Conte had dropped Brazil defender Luiz from the squad altogether following last Tuesday's chastening loss at Roma.
Conte provided an ambiguous answer when asked whether Luiz, who was replaced by Andreas Christensen, had a future immediately after the match.
Conte told Sky Sports: "I don't know. He has to work really hard otherwise they are on the bench or in the stand."
The Italian, who often begins answers with "yes", "no" or "I don't know", was asked about that remark in his post-match media conference.
"Are you talking about the future? But every day you put my future (in doubt)."
Conte insisted Luiz's omission was "only a tactical decision", the best for the team and praised Christensen.
"It's normal," Conte added.
"This can happen to every one of my players, if I see that they are not in good form."
Conte recently stated Luiz was his best defender.
"It can change," the Blues boss said.
Conte's position has been the subject of scrutiny after a mixed start to his second season as head coach.
He ran on to the pitch to celebrate at full-time, but insisted his reaction was down to the magnitude of the opponent.
He said: "I was very happy because we beat a strong team like Manchester United.
"To have this type of performance and to see this spirit, for sure I'm pleased.
"We have to continue and to understand if there is this spirit, this enthusiasm, this passion, we can fight for something important."
There is no love lost between Conte and Mourinho, who preceded the Italian as Chelsea boss. The pair shook hands pre-match but not at the end of the game.
Conte added: "I think that shaking hands two times is enough."
Mourinho said: "You don't want me to go and to chase him in the middle of the pitch.
"There is no problem with it at all. You (the media) are always worried with this thing."
Despite falling further adrift of City after 11 games, Mourinho refused to rule out a title challenge with key players soon to return from injury.
The United boss said: "We are worried, but there are 18 teams more worried than us.
"Eight points in the Premier League, there is still a lot to play (for).
"I hope, I feel, I think, I wish that in the busy period of late November, December, beginning of January, I think probably we are going to be at our maximum strength, with (Paul) Pogba back, Ibra (Zlatan Ibrahimovic), Marcus Rojo back. Probably we can be on a high."
Mourinho last month issued a veiled criticism of Conte for "crying" about injuries. Conte could not resist a retort on Sunday.
"When you have 24 players in your squad and you have one, two, three injuries, it's not a worry," Conte said.
"The problem is if you don't have 23, 24 players in the squad. It's totally different."