The two teams meet tonight.
"It will be a delicate encounter in a wonderful stadium," said Siena boss Sannino.
"I always like to be against the grain, but I think the Giallorossi will be the revelation of this season.
"I know how they work, holding possession, spreading the play around the field. They have an attacking mentality and play with seven forwards.
"We're going to Roma with great respect, knowing we are playing against real champions, but facing them must be a source of pride for us and further motivation to make our fans happy."