The Swansea midfielder has returned to something near his best in recent weeks.
The Iceland midfielder is a key man in the Swans' first team, and is currently their joint second highest goalscorer alongside Bafetimbi Gomis.
He has struggled for his best form for the majority of the campaign, although recent weeks have seen that pick up alongside his side’s performances.
And Guidolin says in his opinion Sigurdsson is a very, very good player but he believes he is capable of scoring more goals moving forward.
“My opinion is Gylfi is a very, very good player,” he told Wales Online.
“I think he can score more. He has quality; he can run in space, he played very well between the lines. He is clever. He's an offensive midfielder with quality.”
Guidolin will now be hoping that Sigurdsson can manage more goals between now and the end of the season to boos their relegation fight.
The Swans have struggled in that department this season as they have only managed to find the back of the net 23 times, the joint second lowest tally in the Premier League.
That demonstrates they will take the goals coming from anywhere if they can help ensure their Premier League survival, and they’ll certainly hope that the midfielder can be a regular contributor in the games remaining.