The Argentina international picked up a hamstring problem in Barca's 4-1 Liga win over Betis in November 2013 and has since been out of action.
Messi missed Barcelona's first game of 2014 against Elche - despite getting the medical green light ahead of the game - but will now make his comeback in the home game versus Getafe.
"Leo is feeling good. He has been training without any problems and is ready to play," Martino stated at a press conference.
"Everybody is happy that he is back again. We will decide on Wednesday whether Leo will feature from the start or begins on the bench."
Martino insisted, though, that he would have no qualms about starting Messi despite his lengthy spell on the sidelines.
"Maybe’s he’s lacking match sharpness, but being Leo I don’t think that’ll be a problem," he argued. "Messi gives everybody confidence and makes us better. Everyone feels better with him alongside them.
"At the decisive moments, having Messi and the whole group fit is the best thing that could happen. This way we’ve always got more options."
Meanwhile, Barcelona will be without Dani Alves, Xavi and Marc Bartra after the trio were struck down by injury and illness.
"Dani Alves has only just recovered from flu," Martino explained. "He needs some more training before he will return.
"Bartra had some physical problems last game. He is fine again now, but we are not taking any risks. The same goes for Xavi."
Martino added that, because it is the Copa del Rey, Jose Pinto will take over in nets from first-choice goalkeeper Victor Valdes.