The Duchess of Cambridge is likely to miss England’s Euro 2020 semi-final at Wembley and the rest of Wimbledon because she is self-isolating after coming into contact with someone who had Covid.

Kate attended England’s last home match, against Germany, and was expected to return to the royal box on Wednesday for the match against Denmark. The duchess, who is patron of the All England Club and a keen tennis fan, was also expected at forthcoming Wimbledon matches including the men’s and women’s finals this weekend.

But she is unlikely to appear for any public engagements for the next week because she has been self-isolating at home since last Friday. Kate was informed she had been in contact with someone who later tested positive after returning from Wimbledon on Friday afternoon.

A spokesperson for Kensington Palace refused to say whether the contact was made at Wimbledon. The palace said: “Last week the Duchess of Cambridge came into contact with someone who has subsequently tested positive for Covid-19. Her Royal Highness is not experiencing any symptoms, but is following all relevant government guidelines and is self-isolating at home.”

Asked if she would be attending Wembley or Wimbledon this week, the spokesperson said: “That remains to be seen.”

According to NHS guidance, anyone who has been in close contact with someone who has Covid usually has to self-isolate for 10 full days. This would rule out Kate attending the Euro 2020 semi-finals or final at Wembley and any more matches at this year’s Wimbledon.

Kate was seen applauding England’s 2-0 win against Germany at Wembley last week alongside William and their son George.

It is understood that Kate, who has had two doses of Covid vaccine, was alerted to the contact on Friday afternoon. A palace source said she had taken lateral flow tests before her engagements at the Euros and at Wimbledon and both were negative.

Kate had been due to spend Monday with William celebrating the 73rd anniversary of the NHS at two events. The couple had planned to attend a service of thanksgiving at St Paul’s Cathedral in honour of the health service, and in the afternoon host a “Big Tea” at Buckingham Palace for NHS staff, in their roles as joint patrons of NHS Charities Together.

Kate’s last public event was her visit to Wimbledon on Friday, when she toured the venue, meeting staff in the museum and the Centre Court kitchen and sitting with the former tennis star Tim Henman to watch Jamie Murray play in the doubles.

William contracted Covid last spring and was able to carry on with telephone and online engagements while he was treated by royal doctors, but was reportedly hit “pretty hard” by the virus and at one stage struggled to breathe.

The Prince of Wales caught the virus during the same period but had milder symptoms, although he lost his sense of smell and taste for a time.