Naismith scored within four minutes of his introduction as a second-half substitute in the 3-1 FA Cup fifth round win over Swansea City at Goodison Park, but was forced off the field in the closing stages following a nasty collision with Jordi Amat.
Manager Roberto Martinez is confident the forward will be able to train as usual this week in the build-up to next Saturday's clash with Premier League leaders Chelsea, but the 27-year-old will be monitored to be on the safe side.
"Steven's OK," confirmed Martinez
"We're going to check him in the next 24 hours. He had a bit of a delayed concussion.
"When he had the knock he was okay, then he became a bit dizzy and he couldn't remember much of what was happening.
"At that point we couldn't take any risks.
"We'll observe him over the next 24 hours but we're hoping he'll be fine and he'll be able to join the group for this week's training."
