England’s Six Nations’ hopes would be given a huge blow if Smith is ruled out as fellow fly-half Owen Farrell is ineligible for selection following his move from Saracens to French side Racing 92 last week.
Farrell had already made himself unavailable for this season’s Six Nations in order to focus on his mental well-being and Smith was a leading contender to fill his boots.
Smith left England’s training camp on crutches and headed for a scan after his session had been cut short.
England attack coach Richard Wigglesworth told several national media outlets: “Hopefully it’s very precautionary, but if he is not (available) it would definitely be a blow for us.
“It wasn’t a big incident. He was just jogging, but he pulled up and happened to be right next to a physio by the sideline, so they walked off after that. All the usual stuff (medical assessments) will happen.”