Members of his family and his girlfriend Sasha Attwood were in the home when it was targeted by burglars while City were playing Everton on December 27th. More than 1 million pounds ($1.27 million) worth of jewellery and watches were reportedly stolen.
"He's a lot better of course," Guardiola told reporters on Friday.
"When you're at home and the people come inside, you are scared, so it's normal," the manager added. "So try to be relaxed and try to make the perfect environment so it will not happen again."
Grealish said he was "devastated" by the robbery.
"The people that commit these terrible crimes have no idea of the damage they cause to people's lives," Grealish wrote in an Instagram post. "I hope they are found and brought to justice so no other family has to go through what we have."
City's head of security Barry South is working closely with the player and his family, Guardiola said.
The robbery was the latest in a string of home invasions of players, including former Manchester City defender Joao Cancelo who was attacked during a burglary in 2021.
Guardiola said South met with City players last season to stress the importance of security.
"(South) said 'This is the reality, you have to be careful, you have to prepare,'" Guardiola said. "When you live in an apartment maybe it is easier, but in the countryside with big houses... and not just in UK, it happens in Spain, it's a reality in Catalonia (his birthplace), in Italy and everywhere."
