Baines has been sidelined since May with an ankle injury, but featured for the Toffees' U21s in their Premier League International Cup clash with Porto B on Sunday.
"Physically Leighton is fine from a medical point of view," Martínez said ahead of Saturday's clash with Bournemouth.
"Now it's about giving him the right sort of introduction. More than anything it's about confidence, about going into a 50-50 challenge without being fearful because of the way he got the [second] injury by blocking a ball, not by stretching.
"It's about preparing his body to be physically strong, but it is great to see him back in training. It's about giving him exactly what he needs, not rushing him back and losing him for the rest of the campaign. We can use his freshness and experience for the rest of the season."