The Tigers, who sit third in the Premiership behind Saracens and Exeter, suffered a shock loss to struggling Newcastle on Friday.
"The team that played at the weekend was good enough [to win]," Cockerill told BBC Radio Leicester.
"We know that the players we put on Friday can perform better."
Their next opponents Harlequins are only a point behind them despite having won two fewer games.
Cockerill says Leicester have gone back to basics in training as they look to pick up their first league win in the three weeks.
"We revisited some of those fundamentals this week in training," he said. "We have to work hard, get our mindset and attitude right.
"In sport sometimes you don't play as well as you would like to and in a scientific world, sport is not an exact science."
Leicester Tigers director of rugby Richard Cockerill has said his side are "far from a crisis point" but need to get their "mindset and attitude right".