Zaccheroni is convinced they can build on recent performances.
"I expect to see further improvement from the team after performances against Cagliari, Inter and Bari," he said.
"We are facing a team that is very concentrated and gives its absolute best on home turf. It's true that Sampdoria's results have reduced our chances of finishing fourth, but we will not give in.
"We've got to do our job right to the end. I still believe in a Champions League place and the lads know it too."