Roma punched above their weight last season but are struggling to find their feet in the opening weeks of the new campaign.
Roma, who finished runners-up in Serie A last season, have registered just one point from their opening two league games.
Last weekend's 5-1 debacle at Cagliari and their 2-0 midweek defeat at Bayern Munich in their opening Champions League group game have put Ranieri under pressure.
To complicate matters, the Giallorossi face a frantic 10 days with games against Bologna, Brescia and Inter Milan before returning to European competition to face Cluj on September 28.
Roma midfielder Daniele De Rossi believes he and his team-mates must rediscover their winning touch immediately.
"We have to return to be a top team," he said. "We have to start getting results and do the talking on the pitch."
Bologna travel to the Stadio Olimpico also searching for their first win of the campaign.
The Rossoblu lost 3-1 at Lazio in the last round but despite the setback, coach Alberto Malesani believes his team are showing signs of improvement.
"I don't think the 3-1 defeat at Lazio does justice to my team," said Malesani. "I believe it was a levelled game.
"I think my team can do well this season.
"We are trying to adapt in the early stages of the campaign but the important thing for me is to put the best Bologna possible on the pitch."
