Martinez has not had long to bask in the afterglow of Premier League survival, with stories immediately surfacing about the future of some of the Latics' key players.
N'Zogbia is one player that has been linked with a departure from the DW Stadium - after being the subject of a late January transfer bid from former club Newcastle United - but Martinez insists he will only allow the player to leave for a club that offers the chance of top European football.
"Charles has improved every year. He's scored 10 goals a season for the past two years and taken on more responsibility. He's been captain. I think he can take on more responsibility on the pitch and I still think he's got a role to play for Wigan Athletic," Martinez said.
"He knows I wouldn't stop him from playing in the Champions League. We cannot offer that and there are a few players here who fall into that category of being able to play in the Champions League.
"If a club comes in for Charles that is not in the Champions League, then I would say 'no'. If I don't see that the club can offer him a different football project than ours then we are not going to sell."
Other players, including Hugo Rodallega, have been linked with an exit from the club - especially as Wigan are working on one of the smallest budgets in the Premier League. But Martinez is insistent his rules for N'Zogbia extend to all of the other important members of his side, regardless of the transfer fees that might cost them.
"We don't have much money to spend but we don't have to sell anyone and, for me, it is much more important that we keep the group together," he said. "Financially we can keep our players because we are in the strongest financial position we have been in. We are very healthy."
Martinez believes Wigan could earn a top 10 finish next season.
"The priority now is the playing staff,'' he said. "We will speak to our out-of-contract players and then apart from that, it's making sure we improve the squad. This window is going to be very important in terms of getting the right balance and wanting to improve what we've got.
"I feel there's something special in the dressing room and we need to make sure we maintain that.
"It's been a pleasure and a privilege to manage Wigan over the last two seasons and I feel we need to make sure we move on now. We need to start next season in the right manner and if we get a top 10 finish it will be unbelievable.
"The chairman has always been the main person. He's allowed me to work and has always been there to allow my work to continue.''