The Spurs manager, Martin Jol, described the challenge as "horrific", claiming that Lee would be out for at least two weeks after sustaining bruising above his knee from Sommeil's stud-first tackle after Wiley had blown for an earlier foul.
The FA are anxious to find out Wiley's version of events as they can take action only if the match official confirms he did not see the incident.
Given Wiley was running towards the scene of Michael Brown's thunderous yellow-card challenge on Joey Barton that occurred seconds earlier, it seems unlikely he did witness Sommeil's tackle, leaving the FA free to launch a charge against the French defender.
Under the new fast-track system, the FA would hope to launch a case against Sommeil within 48 hours, although any ban would probably not take effect until after City's FA Cup tie with Scunthorpe at Eastlands tomorrow.
Jol said: "Lee said it was the worst tackle ever and I believe him. It looked a bit horrific. I can understand why the referee missed it because he was focused on the first tackle. Lee has bad bruising on his knee."
Stuart Pearce, the Manchester City manager, will take action after he has assessed the incident. "I only saw it once in real time and didn't have a good view," he said. "If it was a poor tackle I will tell Sommeil it is unacceptable."
The 18-year-old Aaron Lennon was Spurs' star player in the 2-0 win and Jol said: "Sometimes he is a bit anonymous. Against City he was a personality. That is what I like. He will be a big player in the future."