Kate is due to be unveiled as patron of the Rugby Football Union "imminently," sources have told The Daily Mail.
The Duke and Duchess of Sussex had to give up their patronages following their decision to step back as senior royals in March 2020.
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Harry was vice-patron of the RFU from 2010 until 2016, when he took over as patron from the Queen.
The Duke was thanked for his "time and commitment" by RFU's Chief Executive, Bill Sweeney in a statement last February.
Harry, William and Kate at a Six Nations match in 2007
Harry's sister-in-law Kate is a sports enthusiast and has attended rugby matches in the UK, as well as the Six Nations tournament in Paris in 2017.
The Duke of Cambridge is also patron of the Welsh Rugby Union. England will take on Wales at Twickenham on Saturday 26 February in the Guinness Six Nations 2022.
The Duchess playing rugby with young French fans in Paris in 2017
In a piece for Vanity Fair in 2014, Kate's sister, Pippa Middleton, wrote about her family's love for the sport: "Rugby was a big thing for our family, and the focal point was international matches, which were often played on Saturday afternoons and were as much social as sporting occasions.
"We'd plan our weekends around the big matches, a quick bite to eat at halftime or lunch on our laps, typically a chicken potpie or something equally cosy and English. If we lost, my dad would be in a state of despair for the rest of the afternoon, as if he'd actually lost the game himself."
It comes after reports that the Duchess is poised to become the Grenadier Guards' new colonel, after the Duke of York was stripped of his military affiliations and royal patronages as he faces a civil sexual assault trial in the US.
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