The Latics take on City in the Premier League after the international break and Martinez insists that he would rather work with the players at his disposal than the multi-million pound stars at Eastlands.
Wigan lost 2-1 to Hull at the weekend while Mark Hughes's side are sitting pretty in fourth place in the table, but the Spaniard says his squad have progressed massively in recent months.
"They have one of the best squads in the league in terms of numbers and the quality to be contenders," he said in the Daily Star.
"When you go out to buy the best it can go wrong sometimes but when you look at what they've bought recently it almost resembles how you play a computer game.
"But they now have a fantastic squad and Mark Hughes has them playing as a team. Having said that, I wouldn't swap my squad for Man City's, no way.
"In the three months we have been working together we've progressed massively and we believe in our squad."