The Latics dropped to 19th in the table over the weekend, with defeat at home to Sunderland exposing their defensive shortcomings.
Antolin Alcraraz has missed almost the entire campaign and Ivan Ramis has been ruled out for the remainder of the 2012/13 season, which has left Martinez rather short of options.
The Spaniard has admitted that fresh faces are a must if he is to reassemble his backline for the second-half of the season:
“What is clear is that we weren’t strong enough defensively,” he is quoted by Sky Sports.
“If Ramis had been on the pitch it would have been a very different situation. I need to make sure we rectify that and bring someone in who will give us the same strength Ivan was giving us.
Although he is still seeking additions, one signing Martinez has made this month has enjoyed a solid start to lift at the DW Stadium.
Angelo Henriquez arrived on loan for the rest of the season from Manchester United recently and notched his first goal for Wigan against Sunderland.
Martinez believes that the 18-year-old has all the attributes to be a real success in English football:
“Whether he is scoring or not, Angelo has the profile of a goalscorer, his movement off the last man is fantastic and he has that knack of being in the right place.
“Scoring on his Premier League debut is going to do a world of good for his confidence but I don’t think it will change his way of playing or the high esteem he holds himself in.”