The 20-year-old crashed into the France goalkeeper as he charged towards goal late in Sunday's 0-0 draw at Goodison Park, catching Lloris in the side of the face with his knee and rendering him unconscious.
Lloris was controversially allowed to play on after coming to his senses, but Lukaku was unable to continue and was replaced by Nikica Jelavic.
Manager Roberto Martinez will now have Lukaku’s injury checked ahead of their trip to Crystal Palace on Saturday, but he is hopeful that the Chelsea loanee will not have to miss any game time.
"We will have to assess it, it seems like a dead leg and nothing serious," he told the club's official website. "Unfortunately, he had to come off at that time."
Lukaku was yellow carded by match official Kevin Friend for his part in the incident, a decision that Martinez did not agree with.
"I saw it as a complete accident," he added. "Rom is powerful man who tried to get there first. I didn't see the reason for a yellow card - I did see it as a little bit harsh."
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