Martinez is pleased with the options he has in his squad, at least when everyone is fit, but would like to add one more wide player before the end of August.
Everton have been linked with a loan deal for Chelsea winger Christian Atsu, but no deal has been done yet and Martinez was not willing to talk names when he spoke after the 3-1 friendly defeat by Celta Vigo at Tranmere's Prenton Park.
"It's only one position (we need)," Martinez said. "We want to take as long as we can to see how quickly we can get the injured players back to being available for the first-team.
"Probably another body would help for the September month when we have three competitions to fight for, and we'll carry on working hard on that.
"Wide player is the position we want to bring in but in terms of names, it is too early to mention to our fans.
"But we are pleased with the numbers and the quality we have in the squad now. We have a couple of young players we know are ready and they are going to help, so the numbers are strong.
"All it is now is making sure that every day we sharpen up individually and as a team."