With out-of-towners Melbourne and North Queensland contesting the decider, ticket sales have been much softer than usual, with the league turning to Sydney juniors as the answer to fleshing out the grand final crowd.

An NRL spokesperson strongly denied up to 20,000 tickets were being handed out, as some industry insiders suggested on Wednesday, claiming the figure was only a few thousand. In any event, the match is not expected to sell out.

The league is using its PlayNRL Rewards system to facilitate the junior ticket handout. An email went out to select junior clubs earlier this week, encouraging players and volunteers to redeem their free grand final ticket from 9am Wednesday morning.

A different password was sent out in each email, with the password needed to redeem the free tickets.

"You can use your PlayNRL Rewards password to redeem 1 ticket for the Storm v Cowboys Grand Final at ANZ Stadium on Sunday," the email said.

PlayNRL Rewards offers juniors aged 15 and under, volunteers, coaches and officials free entry into one NRL match each round throughout the season.

It's a slightly different system to yesteryear when junior players would be handed a pass with a barcode that allowed entry to every match across the round.

Fairfax Media understands the NRL has also distributed parcels of grand final tickets to select junior rugby league clubs across Sydney. The same was done for last weekend's preliminary final between the Sydney Roosters and North Queensland, which attracted 28,108 fans to Allianz Stadium.

One club president said he received an allocation of 20 tickets to the grand final, and 20 to last week's preliminary final.

It's not uncommon for the NRL to distribute free tickets to juniors and volunteers for premiership matches, State Of Origin encounters and even past grand finals.

South of the border, tickets to Saturday's AFL grand final between Richmond and Adelaide are virtually impossible to come by, the majority of which are split between club, MCC and AFL members.

About 100,000 fans are expected to pile into the Melbourne Cricket Ground on Saturday, following the 94,258 who watched Richmond beat GWS at the venue last weekend.

But the AFL has the luxury of a traditional Melbourne club in its grand final while the NRL has had just one Sydney team in its showpiece game since 2014.

Return flights to Sydney from Townsville have sky-rocketed to almost $1000 this weekend, forcing many Cowboys fans to stay in North Queensland and watch the game at home.

But the presence of the PNG Hunters, who won the Intrust Super Cup in Queensland last weekend to set up a showdown with NSW Cup winners Penrith, is set to attract thousands of fans from Papua New Guinea.

Extra flights from Port Moresby have been scheduled to accommodate demand.

The NRL remains hopeful Sunday's decider at ANZ Stadium will sell out.

"Ticket sales for the NRL Telstra premiership grand final are strong, with rugby league members and fans from across the country snapping up tickets to Sunday's decider," an NRL spokesperson said.