Seven months have passed since Lazio last won on the road in Serie A.
They lie eighth in the standings thanks to their good performances in Rome, however.
Last weekend's 2-0 win over Livorno saw the Biancoceleste record their fifth victory at home this season, but with just four points collected on the road - all from draws - Petkovic knows his team must stop the rot.
"It's imperative that we start winning on the road," Petkovic said. "Four points out of a possible 24 is just not good enough.
"We need to play better and show our quality away from home.
"I hope our good performance against Livorno will give my players the necessary confidence to win on Sunday."
Lazio will have to be at their very best if they are to surprise Hellas in Verona.
Andrea Mandorlini's side have won seven of their eight games at home this season.
Hellas go into the encounter on the back of a goalless result at Catania that lifted the Verona outfit to sixth place, six points clear of Lazio.
Few could have predicted that Hellas, who gained promotion to the top flight this summer, would go into the Christmas break in the top half of the standings.
Hellas could even leapfrog Inter Milan in the table if results go their way this weekend and end the year in an impressive fifth position.
"We are not getting carried away by our results as our aim this season is to avoid the drop," Hellas defender Domenico Maietta said.
"We know we have to get good results at home if we are to avoid the drop and on Sunday we want three points against Lazio.
"We know it's going to be tough but we are ready."
The visitors will be without playmaker Hernanes, who must serve a one-match ban, as well as injured midfielders Alvaro Gonzalez and Pereirinha.
However, the Biancoceleste will be bolstered by the return of defenders Andre Dias and Abdoulay Konko, that have shaken off muscular injuries.
Brazilian midfielder Jorginho, who is Hellas' top scorer with seven goals this season, has recovered from the flu and will play in support of striker Luca Toni.