Livewire forward Devon Smith believes veteran Steve Johnson's value to Greater Western Sydney has been seriously underestimated by those outside the club.

Since the three-time premiership Geelong star became a GIANT in October, most of the talk about his arrival in Sydney has centred on his on-field experience and role as a mentor to the club's young forwards.

Smith, who will be one of the main beneficiaries of Johnson's brilliant footy brain and knowledge as a fellow goalsneak, said the 2007 Norm Smith medallist was not just recruited by GWS to teach – he's a dangerous forward capable of causing havoc for opposition defenders.

The GIANT, 22, told AFL.com.au that Johnson has not lost the tools that have allowed him to kick 452 goals in his 253-game career.

"He's still flying the big fella, he keeps reminding me he kicked three on the weekend and even threw in a seven-point play, so he's still got it," Smith said.

"I think he's had his best pre-season in six years, so if his body can hold up I think he's more than capable of recapturing his best in a fit and healthy side.

"Every time someone goes to a new club they get a new lease on life and I see him really enjoying his football."

Smith will get his first genuine chance to work in tandem with Johnson on Sunday against the Brisbane Lions when he lines up for his first senior game of the year in the GIANTS’ final NAB Challenge match at Metricon Stadium.

After missing two games last year with knee soreness, Smith has been limited in the past month with a similar issue, but said he has managed to complete 90 per cent of his training over summer.

The dynamic forward kicked 26 goals in 2014 when he finished runner-up to Shane Mumford in the best and fairest but booted just 17 last season.

The GIANTS hope Johnson's inclusion will help Smith's role as a small forward while also adding more flexibility to the team.

"It's always good fun the NAB Challenge and we're going in this week with our best team, so I'm looking forward to playing alongside Stevie and getting our forward mix nice and potent for the year," he said.

"It's good that we get a chance before round one to mix it up.

"It's good to have Stevie there for myself because if he wants to go into the midfield I can play a bit deeper, or vice-versa, so it's great to have that flexibility.

"Rory Lobb has been outstanding and it's good to see his pre-season form going into games. Adam Tomlinson is ready to take the next step – he's an absolute animal in the gym and I hope he grabs his chance."