The 25-year-old full-back moved to New Zealand Warriors for a world-record fee last year after helping Wigan to a league and Challenge Cup double.
"It's somewhere where I'd never say I'd never want to go back to, so at some point in the future it's very possible," Tomkins said.
"I'll never say never. I'll always be a Wigan fan even if I'm not playing there. I love the people, the town."
After announcing his move to the NRL, Tomkins said he could not picture himself playing for another Super League club should he return to England.
After his spell in rugby union, Tomkins' brother Joel returned to Warriors this season from Saracens.
"As soon as Joel signed they were saying 'oh that must mean you're coming back', but for the time being I'm happy playing at the (New Zealand) Warriors," Tomkins told BBC Radio Manchester's Rugby League Extra.
"Watching it as a fan, I'm waiting on results and seeing where it puts Wigan in the league - I've been much more interested in Super League than I have been watching the NRL.
"When you're playing you're concentrating so much on your own game and who you're playing you're not to bothered about other results."
Tomkins scored 13 tries in his 21 appearances in his first season at this new club but they finished outside the play-off places in 11th.

Pauline King, described by police as a "reclusive hermit", was found at The Avenues on 22 February.
Alexander Kerry, 23, of Kinghorn Road, Norwich, was sentenced at Ipswich Crown Court after he entered a guilty plea.
He denied a charge of sexual assault and the prosecution chose not to proceed on that count.
Ms King died as a result of a sustained assault with a knife and hammer during a burglary at her home, the court was told.
She lived alone in what police described as a "dilapidated" detached house and neighbours said she was a pleasant but reclusive woman.
Kerry was found later the same day wandering nearby streets covered in blood.
Det Sup Paul Durham described it as a "vile murder" which "sent a shudder of fear" through the community.
Prosecutor Andrew Jackson said Kerry, desperate for money after drinking in a Norwich city centre pub, had broken into the home and beat Ms King to death.
He then tried to set fire to the house to destroy the evidence, he said.
The court heard he was left deeply damaged after his father murdered his mother as he and his brother slept at their home in 2002.
Mr Justice Stuart-Smith said he acted with "animal brutality" to murder Miss King and sexually abuse her dying body in an "act of desecration".
He said: "Nothing begins to explain what you did to Pauline King. She must have suffered terribly."
Kerry had a criminal record including violence and disorderly behaviour dating back to his teens, he said.
Jonathan Goodman, mitigating, said his client had "self-medicated" through alcohol and drugs following the almost "unimaginable" events of his childhood.

The futures of Aston and Coventry stations were discussed by West Midlands Fire and Rescue Authority.
The authority, which said it needed buildings for a "modern-day" fire service, approved its budget earlier.
Plans to demolish Aston's Ettington Road fire station, which was built in 1923, will go before planners.
Phil Hales, deputy chief officer of West Midlands Fire Service, said Aston residents would be consulted as part of the planning process.
The authority says that Coventry's Radford Road station, which was built in 1976, is expensive to run and maintain.
A new station at Aston could cost around Â£7.5m, while the Coventry scheme could cost an estimated Â£6.7m.
English Heritage has said it expected to be consulted on the proposal to demolish Aston fire station if the plan was put forward.
"Aston fire station was listed at Grade II in 2010 and recognised as a carefully-designed building which works well with its surroundings and is a powerful symbol of civic pride," a spokesperson said.
Sam Tomkins says he is still open to a return to Wigan Warriors in the future.
[NEXT_CONCEPT]
A man who admitted the "vile murder" of an 82-year-old woman in her Norwich home has been jailed for life, with an order to serve 25 years and six months.
[NEXT_CONCEPT]
Plans to demolish and replace two West Midlands fire stations - one of which is Grade II listed - have been backed by fire service bosses.