The Wigan full back will face the Wallabies just a week after appearing against the Kangaroos as England lost to their Australian counterparts in the 13-aside version of the sport at Elland Road.
Tomkins had been heavily linked with a switch to union before signing a new contract with Wigan that prevents him from becoming a high-profile cross-code convert until 2014 at the earliest.
And despite rumours that his selection for the Babaas could prompt a quick rethink, Rugby Football League chief executive Nigel Wood believes Tomkins' much-talked about union debut will be a positive step for his organisation.
"Sam's selection underlines that imitation really is the sincerest form of flattery. Both Sam and rugby league should feel flattered," said Wood.
"I'm sure Sam will be successful on Saturday when he plays his first match in an unfamiliar code because he's a hugely talented rugby league player, one of many our sport is producing."
Sam's brother Joel became the latest league star to switch codes when he joined Saracens earlier this month, while a host of other big names have tread a similar path in recent seasons.
Chris Ashton, Shontayne Hape, Lesley Vainikolo and Robbie Paul have all represented England following their moves south, while Jason Robinson starred on two tours with the Lions in 2001 and 2005 and became a World Cup winner in 2003.
It's a far cry from the amateur days of union when high-profile names went north rather than south, with only the lure of the 1997 Lions tour bring the likes of Scott Quinnell, Alan Tait, Dai Young, Allan Bateman and Scott Gibbs back home.
"Rugby league has an outstanding track record in developing its own players and is continuing to show union the way ahead. Sam's inclusion in a sport he knows little about is proof of that," added Wood.
"You only have to look at how often union has turned to rugby league players and coaches over the last 15 years to see the calibre of talent that we have in our midst.
"It's obvious to even the most casual of observers why union continues to covet rugby league players whose sheer athleticism and outstanding skills with ball in hand make them extremely attractive to the other code of rugby."