The midfielder moved from Manchester United in January 2012 after falling out of favour under Sir Alex Ferguson.
Moyes was happy to sign Gibson but believes the 25-year-old needs to raise the standard of his performances.
"I think he has the ability but there is a bit more to his game that he can offer," he said in the Daily Star.
"He needs a jab of the whip now and again to get going. I think Gibbo' just needs to realise if you think leaving Manchester United meant life would be easier, it's going to be much harder.
"He needs to become more influential in games. He needs to take control more. At times he does not take it by the scruff of the neck and become the main man."