The South Korean was carried off on a stretcher at the City of Manchester Stadium last night.
The incident didn't overshadow another excellent win for Spurs, who finished the Christmas campaign with a nine-point haul that took them six points clear of Arsenal.
Afterwards Jol said: "It was a horrific tackle and Young-Pyo said that he'd never experienced a foul like that.
"We're not sure how serious it (the injury) is yet but he has bad bruising on his knee. Hopefully he will be fine but if not we have a problem."
Jol added in The Daily Mail, "I can understand why the referee missed it because he was focussed on the first tackle (for which Michael Brown received a yellow card)."