Who's the better goalkeeper between Sanchez and Petrovic?

Djordje Petrovic got the opportunity to become Chelsea's No.1 after Robert Sanchez's injury, and things could not have started any better for him.

After a bright start, he was compared favourably to the Spaniard. Now, however, he's under scrutiny after conceding at least two goals in each of the last seven games.

Moreover, advanced stats suggest that Petrovic has performed worse than Sanchez when it comes to saving shots.

According to fbref, Petrovic has conceded 26 goals in the Premier League (excluding own goals) from 21 expected goals against. It means that he has allowed in five goals more than the quality of shots he faced suggests.

For comparison, Sanchez's numbers are 25 goals conceded from 24.2 expected goals against. His goalkeeping also had a negative impact, but it only amounted to 0.8 xGA.

Curiously, both of them appear to be a downgrade on Kepa who prevented 5 goals against Chelsea last season. He's currently on loan at Real Madrid but is unlikely to be retained by the Spanish club.

Who do you want to be Chelsea's No.1 at the end of this season and beyond? Why?