Dr Carneiro alleges she was sexually discriminated against by the club’s former manager, who allegedly abused her as she went on to the pitch to treat Eden Hazard during the opening day of the Premier League season last August.
She claims that, as she ran on to the pitch during the game with Swansea, Mourinho shouted “filha da puta”, meaning daughter of a whore in Portuguese, at her.
The panel at the London South Employment Tribunal in Croydon was read an extract from Mourinho’s statement in which he conceded that he used the term “filho da puta”, meaning “son of of a whore”, but insisted he had been using it throughout the match.
He said: “Filho da puta is a phrase I often use, all of the players know it. There is no sexist connotation in the use of the phrase – it is just like saying ‘f*** off’.
“In the world of football, a lot of swear words are used.”
He added that Cesc Fabregas had used the Spanish equivalent of the term when a Chelsea player was fouled during the game.
In his statement, Mourinho said: “Cesc and I both speak English well, but in the heat of the game we both swear in our mother language.
“Eva was not on the pitch at that point in time.”
Mary O’Rourke QC, representing Dr Carneiro, said: “He uses the word ‘filha’ because he is abusing a woman.”
In an opening argument, she argues the expression is “very offensive” and that it was aimed at her client because she was the “only female pitch-side”.
Preliminary matters in the case were dealt with on Monday morning, after the parties failed to agree a settlement which would have prevented a public hearing.
A skeleton argument submitted to the tribunal, on behalf of Chelsea FC and Mourinho, stated that Dr Carneiro had been “made an open offer of £1.2 million to settle her claims”.
It continued: “The respondents have taken these steps only because they believe that it is in no-one’s interests that this dispute should be determined through litigation.
“They are conscious that, whatever the facts of the matter, it is likely to be widely and incorrectly assumed that they could have avoided this coming tribunal.”
It continued that contemporaneous documents showed that Dr Carneiro did not consider Mourinho’s actions to be discriminatory.
The skeleton argument said: “The purpose of the discrimination claim was to lift the statutory cap, in order to justify the claimant’s extravagant compensation claim.”
Dr Carneiro is claiming constructive dismissal against Chelsea and has a separate, but connected, personal legal action against Mourinho, who left the club in December, for alleged victimization and discrimination.
The case, which is anticipated to be heard over seven to 10 days, is not expected to begin hearing evidence from the 42-year-old doctor until Tuesday afternoon.
Ms O’Rourke, for the claimant, told the hearing she is likely to take at least a day to cross-examine Mourinho, who did not attend the first day of the case.
Also present during the hearing was Chelsea’s head of communications and PR, Steve Atkins.
Dr Carneiro arrived at the tribunal in a powder blue coat and and cream dress, holding hands with her husband, polar explorer Jason De Carteret.
She was dropped as Chelsea’s first-team doctor last year after then-manager Mourinho angrily berated her and physio Jon Fearn for going on to the pitch.
Their action meant that Chelsea were temporarily down to nine men, and afterwards Mourinho called Dr Carneiro and Mr Fearn “impulsive and naive”.
Dr Carneiro did not appear on the bench again for first-team duties and later parted company with the club.
The tribunal was adjourned until 2pm on Tuesday.