Fly-half Wilkinson, who has not played international rugby since the 2003 World Cup due to a catalogue of injuries, could still tour New Zealand with the British & Irish Lions this summer.
Wilkinson was not named in Sir Clive Woodward's original 44-man squad, but he has the option of adding him if he proves his match fitness over the next few weeks.
Fellow Lions hopefuls Phil Vickery and Mike Tindall will also travel to Canada in a squad captained by Worcester flanker Pat Sanderson.
England face Canada in Edmonton on June 19, when they should progress to the final seven days later against Argentina or the USA - although caps are not being awarded.
With England head coach Andy Robinson on Lions duty, his red rose assistant Joe Lydon will take charge of the Churchill Cup campaign.
"I think it is right that Wilkinson, Tindall and Vickery are announced in our squad," said Robinson.
"If any of them are later called up for Lions duty, then great, they will go with our blessing. If not, they will all benefit from being on the Churchill Cup tour."
Woodward said: "I spoke to Andy Robinson this morning about Tindall, Vickery and Wilkinson being named in the Churchill Cup squad, and it is the right thing to do at this stage.
"None of the players are in the position to confirm their full fitness and so availability for the Lions tour - and if they don't tour with the Lions then they will all benefit from being on the Churchill Cup Tour. We would wish them every success if that is what happens."
Wilkinson made his latest comeback off the bench for Newcastle in their Zurich Premiership clash against Northampton 11 days ago, and he could start when London Irish visit Kingston Park next Sunday.
Since the World Cup campaign, he has suffered two knee injuries, a career-threatening neck/shoulder problem and a biceps injury.
Tindall (foot) and Vickery (arm) are also in Lions contention, although Woodward has yet to make a decision regarding their availability tour. The Lions leave for New Zealand on May 25.