The Spaniard admits his shock at the striker's inclusion in his national squad to face Saudi Arabia but enthuses that mixing with the likes of Messi and Aguero will improve him
The 23-year-old has made a superb start to the season, scoring three goals in 10 games, and was a surprise addition to the international squad for their friendly against Saudi Arabia at the King Faud International Stadium.
Although his scoring rate has only marginally improved since his move to the DW Stadium, Martinez believes that the striker can only improve when mixing with the likes of Lionel Messi and Sergio Aguero.
"Franco di Santo is developing into a top footballer," Martinez told reporters.
"He's only 23 but he's come on a lot. Obviously being called up by Argentina and playing with the likes of Messi and Sergio Aguero is going to do him a lot of good.
"But we still know that he needs to carry on enjoying his football."
Martinez also expressed his faith in Di Santo’s abilities but also admitted he was surprised at his player’s inclusion.
He added: "I could see it coming because I work with him every day. You get a bit biased because you know the player.
"I was a little bit surprised with the knowledge the national team coach Alejandro Sabella has shown because, to know a striker at Wigan Athletic, it shows you that they are incredibly professional in the way they follow their players.
"They've got strikers at Manchester City, Real Madrid and Barcelona and to have a striker from Wigan Athletic with the options they've got... they've got strikers at top clubs around Europe.
"It's a real compliment to Wigan. The way we play probably attracts the interests of national team managers.
"We didn't do before and that's a real compliment. Franco deserves huge, huge credit for the achievement."