Abbiati, who joined the club in 1998, has made over 300 appearances for Milan, winning three Serie A titles and one Champions League crown during his time at San Siro.
The 36-year-old's deal expires at the end of the season and Abbiati admitted that the current campaign could be his last in professional football.
"Will I stay another season? It's normal at the age of 37 that some injury problems will catch up with you," he said.
"We train every day and even the younger players have problems. I'm available though and it's not written that I always have be the first choice.
"I'm available like I said. Obviously if the club says enough is enough, then that's it.
"I'd say that if I don't a sign a new contract here, it's 90 per cent sure that I'll quit playing."
Milan go into Sunday's derby with city rivals Inter nine points adrift of their neighbours and 24 behind Serie A leaders Juventus.
And Abbiati believes Milan's lowly league position makes it even more vital that Massimiliano Allegri's men take all three points as the 18-time champions attempt to recover from a dismal start to the season.
"The derby is always a spectacular match and we probably need this win a bit more than them (Inter) at the moment," Abbiati added.
"We've been doing alright recently. We got the draw on Monday (against Roma) and there was some disappointment because at the end we could have even won it but a draw was probably the right result."