The midfielder, dogged by injuries since his last Three Lions appearance in 2008, scored in his first game for his new club against Birmingham as he looks to revive his career
Hargreaves played just under an hour at the Etihad Stadium and scored the opener in a 2-0 League Cup victory over Birmingham, in his first game after signing from rivals Manchester United.
“He has played 60 minutes for us and now he needs to recover very well,” Mancini told the media.
“It’s important we don’t overdo it with him because if he can become the fantastic player he was, I think he will be important for us and also for the England team.”
The 30-year-old has 42 caps for the Three Lions and played his last game at Wembley in May 2008 against the USA.
His well-documented injury troubles have seen him largely out of action since then, but the Canadian-born holding midfielder hopes for a revival under new boss Mancini, with a view to dislodging the likes of Scott Parker and Gareth Barry in the England side.