La Dea gave up a 1-0 lead after Robin Gosens was sent off.
Gasperini said afterwards, “It's difficult to explain what happened in the second half, because some of the chances we missed were so easy, anyone could've scored them.
“We had so many opportunities to win the game. Globally, we emerge with four points from our two games against Roma.
“We are still in third place and maintain our advantage over the chasing pack. We should've closed it earlier, considering the way the game was going. We need to reflect on this, because some performances were really below par."
He also said: “Some of the misses were just shocking. That's a lack of concentration. It's a pity, because so often our substitutions have been decisive.
“The Gosens red card was also dumb, we more than contributed to throwing this win away. As long as we had 11 men, so for 70 minutes of the match, I didn't see Roma manage a single shot on goal. They only became dangerous afterwards.
“We need everyone to step up and contribute, otherwise it's going to be really tough."