Saka set up Kai Havertz's opener before Declan Rice's 49th minute dismissal was followed by Joao Pedro's equaliser for Brighton.
Saka later said, "We can take it both ways, we had the chances to win the game but going down to 10 men against Brighton is difficult.
"I thought it was a bit harsh for us (Rice's sending off). We just want some consistency. Joao Pedro booted the ball halfway across the pitch in the first half and got nothing for it and Dec got the slightest touch and was sent off.
"It is what it is, I dont want to put the whole game on the referee as we still had chances to win it.
"It has been a good start. Today is a disappointment but it is a long season."
On Raheem Sterling's arrival, Saka added: "Great signing for us, I am really happy to have him here. I am sure he will do amazing for us."