Dean Pay was left bemoaning basic mistakes from the NRL's most disciplined side as Canterbury stare down a critical short turnaround with pressure mounting on his inexperienced side.

The Bulldogs entered Sunday's clash against the Dragons with the highest completion rate in the Telstra Premiership, and emerged smarting from a 40-4 shellacking that leaves them in last place on points differential.

Canterbury's 11 errors against St George Illawarra did not measure off the Richter scale, but several did lead to points, with Pay describing the loss as a significant step backwards for his young side.

"It's not good enough. We've made some progression with these young blokes but again we're going to have our up and we're going to have our downs," Pay said.

"I think it's obviously a real learning curve but you can't make errors and then continue to make errors.

"We need to stop that stem of making those simple, simple errors. We need to make sure we've got some resilience to defend them as well."

The Bulldogs will take on competition heavyweights South Sydney for their annual Good Friday showdown.

Bulldogs: Round 5

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It's a daunting proposition that will be followed by a round-seven home game against fellow strugglers North Queensland, before squaring off with Manly and former coach Des Hasler a week later.

Canterbury had shown genuine progress in recent weeks with an upset of the Wests Tigers and almost the same against Melbourne.

But Sunday's heavy loss had the same shades of earlier thumpings this year by the Warriors and Parramatta, with wooden spoon predictions being doubled down by many as a result.

The Eels' defeat was followed by five changes to Pay's line-up, youngsters Jayden Okunbor and Nick Meaney making strong impressions in particular.

But with stars Kieran Foran and Dylan Napa sidelined through ankle injuries, reinforcements are thin on ground and Pay was tight-lipped on any selection changes.

"We've got to make sure that we jump into our hard work, making sure that we're prepared really well again this week and we need to make sure we don't make those type of errors back-to-back," Pay said.