Suggestion...

If you don't care about the order of the array, then it's not necessary to move the above elemenets down to cover the gap.

Instead, why not just take the element at the top of the array, and plug the gap with that? You will have to move that element anyway, since it goes out of range.
If you want to keep the array as a permutation, then you can do a straight swap. The unneeded element will be taken out of the range, but is still in the array, in case you wanted to find each element again later.