The Gillingham veteran agreed a two-year deal at the City Ground to become the first signing of the summer and Megson is hoping more will follow.
"There is no doubt that we need to bring players in," the Reds boss told the Evening Post.
"If the season started tomorrow we would be in trouble. There are a few things going on and I now think things are going to start picking up.
"I think that is pretty obvious because we have only got 17 players left from last season and the positions we need to fill should be obvious."