Panthers halfback Peter Wallace says Penrirth have to rediscover their defensive steel to stay on course for the NRL finals

Returning playmaker Peter Wallace has warned Penrith need to urgently rediscover their defensive steel or risk coming unstuck in the run-in to the NRL finals.

The Panthers sat atop the ladder two rounds ago, boasting the third best defence in the competition, only narrowly shaded by Canterbury and South Sydney and conceding just 16 points per game.

But since then the Panthers have become porous, with their 35-34 round-18 win over Brisbane followed by a 32-12 loss to premiers the Sydney Roosters drop them off the pace set by table-topping Manly.

Wallace missed the Broncos and Roosters games with knee and ankle problems and returns for Saturday’s round 20 fixture with Cronulla at Bathurst’s Carrington Park.

Wallace says a defensive improvement is key, seven rounds out from the finals.

“Our defence just hasn’t been where it should be that last couple of weeks,” Wallace told AAP.

“For the most part of the year our defence has been great. It has been something we have prided ourselves on and it has helped us to get where we are.

“But last week especially we let in a some soft tries and that is something we really need to improve.

“Our goal-line defence really needs to get better, starting with the next game.

“That is something we have really talked about this week and something we have been focusing on.

“We have to get it right. It can’t keep going the way it has been going.”

The Sharks shocked the Roosters with a 30-28 come-from-behind win a match before the Tricolours put the Panthers away.

Wallace said despite Cronulla’s lowly status as NRL cellar dwellers, Penrith have to get their finals charge back on track.

“This is a real danger game for us,” Wallace said.

“Cronulla showed what they can do under adversity a few weeks ago against the Roosters.

“They have nothing to lose and we have to win to stay in touch with the top teams.”

With Wallace back, Bryce Cartwright returns to the second row alongside Isaah Yeo for the trip to Bathurst, with Adam Docker moving to the bench.

Captain Paul Gallen hasn’t been named to make his return from a biceps injury but he could be a late inclusion.