A knee injury has prevented the striker from featuring for the Blues this pre-season, but medical staff say the Argentine is making good progress on his road to recovery.
Sergio’s last appearance was during a 5-3 win over Chelsea at Yankee Stadium in New York at the end of May as part of the club’s post-season tour of the States.
Since then, the team has scored nine goals in six games, with Edin Dzeko and new signing Alvaro Negredo both contributing to that tally.
Meanwhile, an ankle injury is expected to keep Matija Nastasic side-lined for four to six weeks.
The defender was stretchered off in the Barclays Asia Trophy final win over Sunderland at the end of last month.
With the young Serbian out of action, Manuel Pellegrini is likely to pair Vincent Kompany and Joleon Lescott in the heart of defence with Dedryk Boyata offering the Chilean another option at centre back.
