Lancaster will make his decision regarding which centre partnership to start with after assessing Tuilagi's progress in training over the next few days.
"I watched Manu through the course of last week, I could see he was back to running and changing direction. The tipping point will be how he trains over the next couple of days as to where we go with him," said Lancaster.
"He has missed a few games, but I'm confident we'll be able to use him after a full week's training. It would have been different if he had come back in and we were still undecided on Thursday. There are selection decisions across the field and this is one of them. Billy played well against Scotland and Brad's contribution as always was positive.
"But Manu brings a unique set of skills and attributes to the game and the team, as we saw in his performance against the All Blacks. Genuinely, I'll wait and see how he trains tomorrow and on Wednesday before I make any decisions on the centre partnership."
England's next match will come against Ireland on Sunday.