Smith is still waiting for his first Toon goal and is also one yellow card away from a third ban of the season, with a caution between now and April triggering a two-game suspension.
Keegan told the Evening Chronicle: "Alan Smith plays the way he has played all of his life.
"He is tough and he has always got in where it hurts.
"Those sort of players do pick up yellow cards these days - more than they used to.
"It does not help, but we have to get on with it."