McClaren stepped down on Sunday less than four months after taking the job at the City Ground, leaving Forest with the unenviable task of finding a manager prior to their next outing on October 15.
Forest chief executive Mark Arthur says that the club will use the standard protocol in appointing a new manager which he hopes happens as soon as possible.
"It is very important that we go through all procedures and spell out to anyone interested in the job exactly what the terms of reference are," he told the club's official website.
"We are more determined than ever to have a proper structure at the club and a footballing culture that will stand us in good stead going forward, not just in the coming months but the long term.
"I would hope by the middle of next week that we will have someone in place."