The Racing 92 flyhalf had to leave the field in the third minute of the match against Leinster, who went on to win 15-12.

Lambie, 27, sustained the injury as he made a break for his side, and he said after the match that he would go for scans on Monday to determine the extent of the injury.

"I am not all that uncomfortable right now, but the diagnosis doesn't look all that good," Lambie told RugbyPass.

Asked whether the injury would end his season, Lambie said: "It looks like it, yes."

"Like I said, the diagnosis isn't great.

"I have to wait and see after the MRI scans on Monday, and we'll take it from there.

"But, by the sounds of things, I won't be playing for a month or for a few months. The speculation is that I have done my ACL ligament; that is six to nine months, I guess.

"It is a long road of recovery, but it is not the end. I will be back. Exactly when, I am not sure."

Springboks coach Rassie Erasmus had said previously that Patrick Lambie was one of the overseas-based South African players with whom he had discussed the possibility of returning to the Test squad to face England in the June Internationals.

"I'm not saying that all the players will be in the mix in June," Erasmus said when asked about conversations he had held with players such as Lambie, utility back Frans Steyn, hooker Bismarck du Plessis, No 8 Duane Vermeulen, tighthead prop Vincent Koch, scrumhalf Faf de Klerk and centre Juan de Jongh.

"If the players we have here in South Africa are fit and in form, then those guys won't be in the mix. But I had to make sure if those guys are still hungry and motivated to play for the Springboks. It was more of a fact-finding mission."

South Africa play Wales in the United States on June 2, in Washington DC, before returning home for three Tests against England.