With Wigan fighting against relegation from the Premier League, salt was rubbed into Martinez's wounds with Saturday's FA Cup third-round defeat at League Two Swindon.
The shock loss has highlighted the need for Martinez to bring in fresh faces, with left-back an area of concern after Patrick van Aanholt returned to Chelsea at the weekend after his loan was cancelled by mutual consent.
Speaking to the Wigan Evening Post, Martinez said: "Patrick has gone back to Chelsea, and now we need to finalise a couple of options that we are currently looking into.
"Left-back is obviously one of the positions we will be looking at, although it is by no means the only one.
"It means we have now got our full quota of two domestic loans available to us again, but we need to wait to ensure we get exactly the right players that we need to improve the squad."
