The 29-year-old England international was left out of City's squad for the Club World Cup in the USA, a move that led manager Pep Guardiola to hint at the player's uncertain future.
Grealish had difficulties getting into Guardiola's team last season, which has led him to consider his future at the club.
Grealish trains alone
According to a report in The Telegraph, via Sportal, Grealish is currently working with a personal trainer to regain his form after a significant dip in performance last season.
He's expected to return to City's training ground soon to work with club coaches. The main squad won't be back until July 28th, following their participation in the Club World Cup and subsequent break.
Grealish will continue training separately at the club's facilities until a suitable offer from another club materialises.
The winger managed just one goal and one assist in 20 Premier League appearances last season.