Being called into an extended first grade line-up is nothing new for the versatile forward.

In the past he has been so close to his debut he could almost taste it.

He's been included as an 18th or 19th man only to be left out of the final 17 and forced to watch from the stands.

But this week may be different with his spot on the Raiders' bench for the round-five match against the Cronulla Sharks almost locked in.

However, Fensom won't get excited until he makes his first tackle, pass or hit-up.

''My feet are always planted on the ground at all times so I try not to get too excited until the night before,'' Fensom said.

''You don't want to use all your nervous energy leading up to [the game].

''I think I'll just be training and taking it as just another game until it happens.''

Fensom captained the Raiders' premiership-winning under-20s side last year.

No longer eligible for the junior competition, he has been playing with Canberra's feeder club Souths Logan this season.

If he does play against the Sharks he will be the fourth Raider to make his debut after just five NRL rounds.

Jarrod Croker played his first game against the Roosters in round two, Travis Waddell in round three and Josh Dugan debuted in Monday's 23-18 win against the North Queensland Cowboys.

Justin Carney and Joel Thompson were also members of the under-20s side and played their first NRL games last year.

Fensom joined the top grade for pre-season trial matches and said he wanted to make a good impression in his first regular-season outing.

''In the the trial against Brisbane I felt I handled it [NRL standard] quite well,'' Fensom, 20, said.

''The pace is a bit quicker but I'm happy with my fitness at the moment so I think I'll be right to handle it again.

''We've had three debutants the last three weeks and they've all performed outstandingly so hopefully if I get a chance I can do the same.''