The Scottish champions are coming of three goalless draws in the league ahead of their clash with rivals Celtic at Ibrox on Sunday.
“It’s a concern for us when you go three league games and don’t score a goal,” admitted Smith.
“It’s an unusual circumstance and it does start to become a little bit of a concern.”
He added: “I think the Celtic game is one that every player knows the importance of for the whole club.
“Never mind the league position at the moment, the Old Firm matches are for the supporters, for the bragging rights for a number of weeks before we play again.
“The importance of the Old Firm games is there for everybody to see and it helps alleviate the disappointment of a poor European result.
“We have seen over the last couple of seasons that the outcome of the matches has an effect on the championship.”