Fiorentina will attempt to win their first match and score their first goal under coach Delio Rossi, who replaced the sacked Sinisa Mihajlovic last month.
They also have internal problems, having fined Alessio Cerci and Andrea Lazzari for breaking club rules after the players were spotted in a nightclub in the early hours of the morning last week.
The pair joined Juan Manual Vargas and Houssine Kharja in the doghouse after the Peruvian and Moroccan were disciplined by Mihajlovic for unprofessional behaviour.
"Now we need unity," said Pasqual.
"This is not the time to be causing trouble. I am convinced that the ones who overstepped the mark will accept responsibility.
"I do not know what goes on in their minds, but in the past we used to be able to solve these issues."
Results under Mihajlovic were far from disastrous but the fans became fed up with the team's lacklustre performances.
However, the decision to remove the Serb and replace him with Rossi has so far backfired with a goalless home draw against Milan and 2-0 defeat at Palermo.
Roma will be without top scorer Pablo Osvaldo after he was banned for one game by coach Luis Enrique for lashing out at team-mate Erik Lamela following the 2-0 defeat at Udinese last week.
The Argentine-born forward has apologised for the episode and offered to take his team-mates out for dinner to make amends.
Big-spending Roma began the season with ambitious plans to play like Barcelona, but have managed only five wins in 12 outings and are seventh, nine points behind leaders Juventus. Fiorentina are 16th with only 13 points.
Leaders Juventus, unbeaten after 12 games and with 26 points, are at home to a resurgent Cesena on Sunday while AC Milan and Udinese, two points behind them, have away games.
Champions Milan visit Genoa on Friday and Udinese are at Inter on Saturday.
