Asked about the forward, Martinez said: "Callum McManaman has been through a lot in the last few months. I always said he is one of the biggest diamonds in British football at his very young age. He is a man for the big occasions.
"He hasn't got many starts under his belt but he was typifying what Wigan Athletic is. I couldn't be prouder for him.
"He is not fussed about anything. He is not one of those who wants to wear the best shoes or drive the best cars. He comes in, give him a football and he is a happy man. That's the way he plays.
"The one-to-one situation was a real threat for us all afternoon. It was a very good performance.''