"We have got to find a natural left back; I have tried since I got the news on Brevett and made some enquiries but so far the clubs that they are at are not keen to let them go, so we have to move on to other targets," he says.
"All obviously have the ability to play for us and it is a question of getting one of their clubs to agree to make it happen.
"I am still very positive towards having a new natural left back who will be able to play for us on Tuesday against Bradford - and stay with us for a period of time."
As for his contingency plans for the weekend, he adds:
"I am not giving any secrets away; we have a few possibilities to fill the role at Rotherham.
"I want to keep Kevin Horlock in midfield as much as possible because that is what he has been brought in to do, but we know he can stand in at left back in the manner that he did against Sheffield United when Rufus went off.
"But whether we put Kevin there or find another way of filling in the role everyone is going to have to wait and see on Saturday."
West Ham will be up against former Hammers left back Scott Minto, who left on a free transfer in the summer, and Glenn adds:
"It is ironic we are talking about left backs; Scott had three years or so at West Ham and always gave of his best when he played.
"I am sure he would have liked to have played more but for whatever reason with Nigel Winterburn doing so well he didn't.
"But I am very pleased to see he has got himself a contract and I am sure he will do well for Rotherham."