The Italian has yet to include Cahill in any of his three Premier League squads.
The club captain has won the Champions League, two Premier League titles, the Europa League, the FA Cup and the League Cup since joining from Bolton Wanderers in 2012.
In reference to Cahill's absence, Sarri has claimed that it is not unusual for defenders to take more time to learn his methods.
And according to The Telegraph, Cahill is prepared to stay long enough to learn said methods.
The 32-year-old has been linked with Galatasaray in recent weeks.