Fer failed his Toffees medical with a knee problem after an £8.6million deal was agreed.
He said: "We are short. We said that before the window. We're short of what we want and we tried but it didn't happen.
"We could have tried a little bit earlier, but I wouldn't say money wasn't made available.
"We were disappointed obviously, because Fer is a top player. But we are still one of the contenders to be in and around the top four.
"We had a good January. It's a case of keep plugging away."