N'Zogbia, who won his first cap for France earlier this month, was left out of last weekend's shock season-opening loss to Blackpool. It has been claimed the 24-year-old, who has been linked with Birmingham and Sunderland, has fallen out with Martinez and is looking for a move but the Spaniard insists that is not the case.
Speaking at a press conference on Thursday, Martinez said: "Charles is a Wigan Athletic player and that is the top and bottom. He has been working really hard and been training well. We will have to get used to speculation and rumours and we need to take it as a compliment when other clubs want to take our players.
"Unfortunately this is the instability the window brings to a club like ours. He will be working hard to play in every single game and that is what every player should be doing. "Since he came back from international duty he has been training hard, working really well and fighting hard for his place with everyone else. It is rumour and speculation and something you are not going to stop."