A real stretch to blame the left side for the first goal. They blocked off any way into the box and Saka passed back into the centre were Partey was left in acres if space.
Unless you feel that Perisic should've been closing down Partey I fail to see how he gets the blame for that.
Second goal came down the left but it was Son at fault, not Perisic. Saka came inside, Perisic rightly went to cover the player overlapping Saka, leaving Son, who made zero, effort to stop Saka getting a shot off. Blame there is on Son and Lloris.