The two mature-aged recruits will run out at Etihad Stadium when the Tigers kick off their pre-season against Melbourne and North Melbourne.
The Tigers are in a position to nominate a rookie for promotion before round one as they have less than 40 players on their primary list.
Former Essendon midfielder and new rookie Sam Lonergan will press his own case in the coming weeks after returning to training on Tuesday following ankle surgery.
"I think we've got one spot up for grabs that we can elevate to so that's the beauty of the NAB Cup; you get the opportunity to play the rookies and see how they go," midfield coach Danny Daly told AFL.com.au on Tuesday.
"There's three or four blokes who could be elevated so it's a competition within a competition."
Stephenson acquitted himself well against Paddy Ryder in the second half of the clash with the Indigenous All Stars two weeks ago while Petterd impressed on Friday in the Tigers' intra-club match in a role off half back.
"When we got [Petterd] we thought about what role might be best for him and we thought about a wing role, and someone mentioned he played a lot of footy across half back as a junior," Daly said.
"We've tried him down there and the two games we've had so far, he's probably been our best player, to be honest.
"He's putting his hand up to be elevated to the senior list and he'll play across half back on Friday night and all things going well, he's giving himself every opportunity to be upgraded."
Lonergan's first full training session didn't go completely to plan with the ex-Bomber needing six stitches in his chin in the opening 20 minutes after copping a knock.
Dustin Martin (knee) and Ivan Maric (chin) were others who needed attention on the sidelines after sustaining their own scrapes.
"We haven't had a hit out since our pre-season [intra-club] game on Friday so the boys were looking for a bit of a hit out," Daly said.
"They know there's a few spots up for grabs on Friday night.
"'Dimma' put it to the boys this morning that they need to train well to get a game so as you can see it's been full on."
Lonergan is on track to play in the second or third round of the pre-season competition, along with Troy Chaplin and Jake King, who both resumed training on Tuesday.
Dylan Grimes (hamstring) is in the same category after picking up his workload and participating in the warm-up before running laps.
Daly said first-round draft selection Nick Vlastuin would play on Friday night and remained firmly in contention for round one against Carlton after an impressive pre-season.
"He's a massive chance [for round one], and it will be a good story considering our midfield – it's a pretty strong midfield," he said.
"He'll play this week through the midfield, he's a hard nut, I think he beat Cotchin in a couple of one on ones last Thursday or Friday.
"Damien Hardwick loves that sort of stuff so if you did the round one team now, he'd be in the 23 or 24 no problems."
At this stage, just Nathan Foley (Achilles) is expected to be unavailable for selection on March 28.
Rickey Petterd is a forward in NAB AFL Fantasy. He averaged 47.25 points in 2012. Register your team at our AFL Fantasy Hub.
Jennifer Phelan is a reporter for AFL Media. Follow her on Twitter @AFL_JenPhelan.
