Fabio Simplicio's brace seemed to give Roma a win, but Chievo fought back for a 2-2 draw.
Recent rain and snow had left the pitch covered in mud at the Bentegodi, even when sand was put down to soak up the moisture.
"Roma knew the state of the pitch would take away from their quality and passing movement, so they fielded a more muscular side," pointed out Pioli.
"We tried to counter them ball for ball. Roma did better in the first half, we were clearly the stronger side in the second.
"They played Adriano to act as a marker up front, so they could go past the midfield and get him to hold up the ball. I thought he had a good game."
The Flying Donkeys were 2-0 down, but fought back for a point, while they beat Inter here 2-1 in their last home game.
"We had a bad start to the season on home turf, but have turned the trend around. The team is playing well and, despite the state of the pitch, with a certain quality. I'm convinced we will achieve our objectives this season."