Wigan Athletic boss Roberto Martinez admits he could make four new signings this month.

However, the Latics gaffer also says he could promote from within if he is impressed.

Martinez said: "There are four positions we need to strengthen but that could be strengthening with players we already have in the squad.

"Sometimes you can cover positions with players you have in the squad but by the time this transfer window closes we need to be a stronger squad than we are now for the demands of the Premier League.

"We need that extra competition and there are areas we can improve."