Fans at the DW Stadium have seen an array of international talent arrive at the club over the past few years, including Hondurans Wilson Palacios and Hendry Thomas, Ecuador's Antonio Valencia and Colombian Hugo Rodallega.
The Latics have most recently been linked with a move for Sheffield United defender Matthew Kilgallon, but Martinez's search for new players will go far beyond the UK when the transfer market re-opens.
"We've got a good squad at Wigan with a lot of potential and they are still improving," Martinez told the Wigan Evening Post. "You are always looking to strengthen and our search is a worldwide one.
"We are not just looking at the English market, because some players here can be a little bit overpriced. So I'm looking at Spain, Holland, Scotland, Portugal, Ukraine and South America as well.
"We have strong links there, as we have shown with the players we've bought. We are going to be linked with many players but any who come to Wigan will have to give the squad another dimension, and, crucially, help the players we already have."