Silva returned to Spain over Christmas to be by the side of his partner Yessica Suarez Gonzalez following the birth.

Pep Guardiola revealed that he could miss more matches for City but says the Spain international's family must come first.

Silva said in a statement on Wednesday via his official Twitter account: "I want to thank all of you for the love and good wishes received in the last few weeks. Special thanks to my teammates, the manager and all at the club for understanding my situation.

"Also I want to share with you the birth of my son, Mateo, who was born extremely preterm and is fighting day by day with the help of the medical team."

Silva, 31, returned to play in the 3-1 victory over Watford on Tuesday night for just his second appearance in six matches.

Guardiola said after the match that the midfielder may miss some games in the future but insists it is up to Silva to decide when he is available.

"We are very happy David is back, we don't know how long but he made another exhibition -- he's essential, he showed how important he is for us," the City boss told a news conference.

"He's free to stay or leave, it depends, he wants to stay because he enjoys it but family is the most important thing in life.

"It doesn't matter if we drop a lot of points because he's not here, I'd never push him. Some days he will be here some he will be out, it depends how his family is."

His teammates are supportive of Silva as he goes through a difficult personal period. During the victory over Tottenham Hotspur, which was the first game he missed, Kevin De Bruyne celebrated his goal by making 21 with his fingers -- Silva's shirt number -- while goalkeeper Ederson held up his shirt in the postmatch celebrations in the dressing room.

Silva's former club, Valencia, gave a message of support to the player who spent four years at the Spanish club before joining City in 2010.

Sergio Aguero told reporters after the win over Watford: "He has had some problems, which he is resolving. We are here supporting him.

"Although he has not trained much as he needs to be with his family, he is performing very well. He helps us so much as he is such an important player for us.

"With the quality that David has I would always like him in my team, he is one of the best attacking midfielders around."