The former Man of Steel, who missed the first three months of the 2016 season following knee surgery, was due to return from his latest injury in April but is still struggling to run and may need another operation.
"He tried to run with the plate and he's still struggling so we're debating whether to take the plate out or not," said Wigan coach Shaun Wane.
"If that happens, it's six to eight weeks. We're having a chat to the physios and the specialist."
Tomkins, 28, has made just 16 appearances for his home-town club since cutting short his stay with New Zealand Warriors at the end of the 2015 season to return to Super League.
He missed Wigan's Grand Final win over Warrington in October and England's Four Nations campaign but had hoped to be pushing for a place in the World Cup team at the end of this year.
"I feel sorry for him," Wane added. "I felt personally gutted when he tried to run last week and struggled with it, I could see he was down."
Tomkins may draw encouragement from the experience of team-mate Micky McIlorum, who is nearing his comeback after more than 12 months on the sidelines with a similar injury.
The former England hooker has not played since damaging his ankle in Wigan's World Club Series clash with Brisbane in February 2016 and was forced to delay his comeback in order to have a plate removed.
The 29-year-old is set for an Easter return and Wane says the player could even be fit for the home game against Super League leaders Castleford on Thursday week.
Meanwhile, Wigan's Under-19s took a break from their usual training routine by going through their steps with the Royal Ballet.
The youngsters were invited to London after Royal Ballet officials became aware of their sessions with Wigan-based community project Pianos, Pies & Pirouettes and they were welcomed by artistic director Christopher Powney before going through their routine.
