But Martinez said on Thursday he had not felt the need to strengthen his defence before the transfer window closed.
He reiterated his faith in the regular back-five line-up of keeper Tim Howard, Leighton Baines, Phil Jagielka, Sylvain Distin and new England international John Stones.
"It has been one of those situations where everything that could go wrong in our box has gone wrong," Martinez told reporters ahead of Saturday's game at West Bromwich Albion.
"We are aware of what we have to improve, but the margins are very small. It is not about a need for drastic change or revolution.
"I was never tempted to go into the market. We have centre-halves that I couldn't be happier with. We just need that confidence back."
Martinez said that his move on transfer deadline day for Manchester United midfielder Tom Cleverley "wasn't right".
"On the last day of the window there are always opportunities that arise, and we looked into a couple of those," he said.
"I felt it was an opportunity for us to maybe add a player that could bring something different, but at the end it wasn't right."
Cleverley instead went on loan to Aston Villa.
Everton are fourth from bottom of the early season table with two points from three games. West Brom are one place below them.
Belgium striker Romelu Lukaku should be fit for the trip to the Hawthorns after recovering from a toe injury that kept him out of Belgium's friendly against Australia.
(Writing by Stephen Wood, editing by Stephen Wood)
Share
