Balmain Tigers icon Steve Roach has slammed the defence of recruit Jayden Sullivan after the Wests Tigers' 32-12 loss to the Canberra Raiders.

Right on half-time, Raiders centre Sebastian Kris caught Sullivan having a lapse of concentration in defence, passing to Xavier Savage on the wing - Savage would go on to score with ease, remaining untouched.

"You should be man on man there, what was Sullivan doing in field?," Roach said on Fox League

Former Brisbane Broncos and Queensland lock Corey Parker was also unimpressed with Sullivan's defence, as his lapse in concentration led to an easy Raiders try.

"This is park footy stuff, beautiful awareness from Seb Kris and Xavier Savage," Parker added on Fox League.

"Bud Sullivan on the right-hand side just clocking off and straight away Seb Kris realised that. That is embarrassing."

Later in the game, Sullivan would be substituted out of the match by Benji Marshall in favour of veteran Aidan Sezer with 25 minutes remaining.

"I just said to Aidan [Sezer] before the game, 'There's no real plan for you, it's dependent on what we need' and at the point in the game, I thought we needed a bit of organisation and experience," Marshall said post-match.

"It was a big ask for him to go on [when we're] down 12 points and turn that around and unfortunately, we couldn't get it done."