After the final whistle, City's head of player support and protocol, Manel Estiarte, informed Grealish about the incident, which visibly impacted the player as he rushed to the dressing room.
A source told The Sun: "The family are really shaken. The gang took a lot of watches and jewellery. They executed their raid when Manchester City were playing live on TV and all his family had gathered downstairs to cheer him on. No one was injured but there was a lot of panic. Everyone was terrified as they were all so vulnerable.
"It's an enormous property, so it is understandable why no one heard anything at first. It was also the first time the family had visited so they were unfamiliar with the property. When the dogs went mad, and they could hear people creeping about, they pressed the security panic alarm