Italy missed out on automatic qualification after finishing behind Spain in Group G, while they were afforded arguably the toughest possible draw, with Northern Ireland, Republic of Ireland and Greece their other potential opponents.
Gian Piero Ventura's side travel to the Friends Arena for the first leg on November 10 before hosting the conclusion of the tie at the San Siro in Milan three days later.
And while Buffon is expecting a stern test against Sweden, who were second in Group A behind France but finished above the Netherlands to earn a play-off place, the 39-year-old says the 2006 winners have to be in Russia.
"It's an important target for myself and for Italian football," Buffon told FIFA's website.
"We must qualify for the next World Cup, for our football history and tradition. The play-off will be tough but we need to qualify.
"Sweden is a difficult one. They play a high standard of football. They don't give you any gifts on the pitch. You must achieve the win by suffering and by putting in your best effort, because if you are not in your best shape, you can easily lose.
"I have great respect for them and am curious to see what it will be like to play against them."
But Buffon — who intends to retire after the World Cup unless Juventus win the Champions League, one of the few honours he lacks in a glittering career — demurred when asked if he is the best goalkeeper of all time.
"I like the idea, but I am not the someone who can support that and celebrate myself," Buffon added. "Everyone can choose the best — for someone I might be, for someone else I might not.
"In my case the career and numbers of course tell a lot, but at this level facts are facts and words count for nothing.
"When you are closer to the end of your career, of course you think about all of your achievements and records, and you realise the kind of player you are.
"I'm proud of my 20-year career with the national team and hope to continue for a 21st season too. I think that it's also extraordinary to play in one of the most important national teams for 21 years; maintaining a high standard of performance and staying strong mentally and physically for a long time. It's not so common."