Wigan winger Callum McManaman ruled out for three months with an ankle injury and will miss the European U21 Championship
Martinez thinks McManaman shouldn't be swayed by the mooting interest shown in him by Liverpool.
"I think if one player needs to stay at the club and become an important part of this football club, it is Callum.
"Callum has been a phenomenal player for us but he still needs to work at certain aspects to become the player he can be and will be and the Championship to play week in, week out will be perfect for him."