The Latics are currently in 18th place in the Premier League table after a run of six defeats in their last 10 games.
And Martínez says he wants to bolster his ranks in order to add more competition for places at the DW Stadium.
“We are having a few difficulties, especially with injuries, so we have to find a solution,” Martinez said. “We need to make it difficult to get into our starting XI
“So we want to do some business in January. I think it’s important that every transfer window works in your favour and you finish with a stronger squad.
“But I still feel our most important players are already in the squad – they are just injured.”
MORE: Latest Man Utd news
MORE: Latest Arsenal news
MORE: The latest football news