However, explosive Leicester Tigers centre Tuilagi is fit again after a six month lay-off with a torn pectoral muscle and could offer England an exciting option off the bench.
And while Lancaster is loathe to alter a team that is firing on all cylinders, he admits Tuilagi offers a tantalising option as England go hunting for the title.
"It would be hard to change the starting XV on the back of that performance," said Lancaster.
"If we were to go down the route of using [Tuilagi] on the bench he'd certainly have a big impact.
"We didn't feel that it was right to involve Manu against Wales because of his lack of training time with us. We'd be more comfortable bringing him in for this weekend.
"I haven't spoken to any of the players yet and there's someone who would lose their spot on the bench if that's the route we go down.
"One option is for him to cover wing and we have both Jack Nowell and Jonny May who can cover full-back."