The forward is back at the DW Stadium after a season-long loan in his native Argentina and the Latics boss believes that he can now settle and make an impact in the Premier League
The 27-year-old cost the Latics £6 million in 2010 but scored only one goal for the club, against Swansea City in the League Cup, before spending time on loan at Genoa and then back at his old side.
The Argentina international joined Wigan after scoring 32 goals in 57 games in his first spell at Estudiantes, but has struggled to settle in England. The Spaniard feels that he will be able to adjust at the second attempt, however.
Martinez told the Wigan Evening Post: "Mauro will be joining us next Monday, and we are all very excited about that.
"He has just had a very challenging season at Estudiantes, where it was extremely difficult for the team as a whole.
"But in the second half of the campaign, you started to see the best of Mauro," added the 38-year-old. "He scored plenty of important goals, and he was showing a real enjoyment of his football again.
"Mauro has also had some very good news in his private life recently; he has just become a dad, and we are all very pleased for him.
"I just feel now is the right time for him to come back to Wigan and settle back in to life in England, and be himself as he has been able to do back home."