That scan will take place today, with initial fears suggesting that Wilkinson may have suffered knee ligament damage that could rule him out of England's autumn internationals next month.
"It looks like it is something to do with his left knee. It looks like it is some sort of ligament damage, but we will have to see how it settles down in the next couple of days," said Newcastle rugby director Steve Bates.
"Jonny is a great competitor. He didn't want to come off. We hope it might not be as serious as it looked."
Wilkinson, who missed his club's opening match of the season, had been due to be rested for this Friday's EDF Energy Cup encounter with Newport Gwent Dragons at Rodney Parade. Instead, Wilkinson's absence will be enforced as Newcastle and England nervously await the outcome of yet another medical assessment.
Wilkinson toured with the Lions in 2001 and 2005, playing in five of the six Test matches against the Wallabies and the All Blacks. A place in next summer's squad to face the Springboks would give the World Cup winning hero a chance to surpass Gavin Hastings' record of 66 Test points for the tourists.