The Biancocelesti claimed a 1-1 draw in their last Serie A match but Petkovic was critical of their performance, and he has now demanded a response in their next fixture against Napoli on Monday evening.
"We did not read the match properly," Sky Sports News quotes him as saying. "We were not ourselves and we never came to life."
"We are a long way off the consistency we're looking for. We need to improve.
"Our performance at Sampdoria was below par and I expect a response from my players on Monday."
Lazio are currently ninth in the Serie A table, level on 17 points with five other teams.