The Tigers' defence has been exceptional, contributing to a run of five straight wins to move up to third in the standings with three rounds to go.
Victories against Bath and Wasps saw them concede just six points over the second half of both games, a statistic that shows their hard work on both their fitness and their defence is paying off.
Saturday sees east midlands rivals Northampton Saints visit Welford Road and another win could go a long a way to securing a play-off spot.
O'Connor admits he has been encouraged by his team's ability to keep opponents away from their try-line but says it will count for nothing if they do not maintain their form against the Saints.
"One of the most pleasing things about the last couple of wins is that we have conceded six points in two second halves of rugby," he wrote in the Leicester Mercury.
"That says a lot about how hard the guys are working and how big a contribution the bench is making.
2There are a lot of positives for us but they mean nothing if we stumble at home to Saints.
"So we know we have got to keep working hard, keep making sure we get better at all the things that are going to be important at the back end of the season."