Sezer started the season as the Raiders' first-choice No.7 and played in the opening two games before an oblique injury ruled him out for two weeks.

Williams has guided Canberra to wins against the Newcastle and North Queensland, which saw Stuart name Sezer 18th man for their clash with Parramatta last Sunday.

Williams orchestrated a third straight victory with the 19-0 win over the Eels making the Raiders 4-1 and equalling their best start to an NRL season in 14 years.

Stuart conceded he won't change a winning formula and Sezer will again watch from the stands when Canberra host the Broncos.

"It's hard, I find it as one of the more difficult parts of coaching where you've got a guy sitting out there and not getting his starting spot" Stuart said.

"But it's lovely to see Sam taking his opportunity in playing the way he is, it's what you've got to do when you get into first grade, when you get your opportunity you've got to grab it with both hands and that's what Sammy is doing at the moment.

"[Sezer] is one of the leaders in the group and a real team-first person and he's a humble guy. Aidan is there for the support of the team at the moment and there's going to be a day we're going to need Aidan running the team again."

Stuart could be forced into a change in his forward pack after Joe Tapine left the field with an ankle injury that will require scans on Monday.

It continues an injury-plagued three seasons for the New Zealand international but Stuart is hopeful the star back-rower has avoided serious damage.

"We've got to get scans tomorrow, I've got fingers crossed it's not a break and just ligament damage," the coach said.

"Taps unfortunately has had a little bit of a tough start to the season but he's got a good attitude and is a mentally tough kid so he'll bounce back, but I feel for him because he just can't get going at the moment."

Australian Associated Press