The Turin giants saw their 12-game winning run in the league halted in Saturday's 1-1 draw at Lazio.
Scudetto contenders Roma beat Hellas Verona 3-1 on Sunday to turn up the heat on their title rivals.
"The situation in the league worries me as much as it did before this weekend," Buffon told Gazzetta dello Sport. "The only exception is that now we have two points less than we did before with respect to Roma.
"But two points changes little.
"We already knew that Roma were a strong team.
"Right now the battle for the Scudetto is between Roma and Juve, but this could change in the next few weeks. Who knows?
"There is still a long way to go in the season."
Buffon will sit out Sunday's match against Inter Milan as he serves a one-match ban after being sent off against Lazio.