The Giallorossi have won all three of their opening games and are level on nine points with Napoli at the top of the Serie A table.
It is an unusual start for Roma, who have not won their opening three league games since the 2007-08 campaign.
"A long time had passed since we last had such a good start," Totti said."I think that with respect to previous seasons, we have a more united group, capable of making a difference at any time.
"I think with the fighting spirit the team is showing we can have a say but the season is long."
Totti, who on Friday signed a two-year contract extension which will keep him at Roma until June 2016, is looking forward to the derby but insists his team is not desperate to avenge its 1-0 Coppa Italia final defeat to Lazio earlier this year that left the Romans out of European competition.
"For us and for the whole city this game is different from any other," he said. "It's normal to feel more will and determination in the derby.
"Our defeat in the Coppa is a close chapter.
"We are focusing on the present that is more important than the past."
The game at the Stadio Olimpico will see Roma tactician Rudi Garcia experience his first derby.
The former Lille coach replaced Aurelio Andreazzoli earlier this summer.
Rivals Lazio will be keen to remind Roma of their recent results against them.
The Biancoceste have not fallen to their neighbours in their last five meetings.
Lazio are in good form having beaten Chievo 3-0 at the weekend to record their second win of the campaign.
Vladimir Petkovic's men also enjoyed a strong start in the Europa League, a 1-0 triumph over Legia Warsaw on Thursday, courtesy of an Hernanes' goal.
Petkovic believes the pressure will be on Roma.
"They will have to try to win because they play at home," Petkovic said. "But we will do everything possible to make sure that doesn't happen."Roma has a lot of confidence due to their three straight wins in the league but I hope they still have a little of bit fear after our recent wins against them, including in the Coppa final."
The visitors welcome back midfielders Antonio Candreva, Cristian Ledesma and Senad Lulic as well as forward Miroslav Klose, all rested in midweek.