Smith thinks that if Pierre-Emerick Aubameyang does leave, the club should still look at Martinelli as a prospect rather than as a striker who can fill the boots of the Gabon international.
"There's no question they've got talent inside the club," Smith told Sky Sports. "I'm a big fan of Martinelli in particular. I think he's got a great attitude and a wonderful eye for goal as we've seen on a number of occasions already.
"There's definitely a lot to come from him but you have to be careful you don't put too much responsibility on young shoulders. They need to be nurtured."