"I'm delighted to be joining the Common Goal team, it's a fantastic initiative," said Weir. "It helps to raise funds and awareness for causes that I am passionate about, such as gender equality and female empowerment, as well as providing necessary relief for those in need during the current pandemic.
"Teamwork is a fundamental part of football, and Common Goal epitomises the importance of working as a team to achieve a shared ambition."
Manchester United midfielder Mata became the first to sign up in 2017 and the fund has raised nearly €2 million for football charities around the world.
"At this time of crisis, the need for teamwork is clear," said Mata. "Collaboration is the best shot we have of ending COVID-19, and tackling the other challenges we face.
"It gives great hope to see so many diverse players stepping forward to work together on providing immediate solutions.
"Welcome to the team Caroline, Common Goal member number 150."