"We have started season well, with a victory in the first match and three important points,"  said Carrera, who is standing in for the suspended Antonio Conte.

"However we need to improve because there's a long season ahead of us and those improvements must be quick."

Juventus shrugged off a penalty miss from Arturo Vidal to run out comfortable 2-0 winners against Parma.

Goals from Stephan Lichtsteiner and Andrea Pirlo sealed victory for the reigning champions on Serie A's opening weekend.

The Switzerland international turned in from Kwadwo Asamoah's cross just after the interval, atoning for his Chilean team-mate who had seen his kick saved from the spot by Antonio Mirante.

Three points were secured by Pirlo, whose low free-kick originally appeared to have been stopped before it was allowed on the advice of the fifth official.

"At half-time I told the guys to play as we did during the week in training," Carrera said.

"I told them to play at a much higher tempo and they were good, they understood what I asked and completely changed the rhythm of the match in the second half."

Juve's next Serie A test comes next Sunday when they visit Udinese.