71-year-old Graydon, who famously guided the club to promotion to the Championship in both 1999 and 2001, is hoping Clarke can bring the good times back to the Banks's, but admits there is a lot of work to be done before the club can begin to compete with the title-chasers in League Two.
Speaking to Express & Star reporter Joseph Masi, Ray said; "When a team has been relegated there is a black cloud over everybody – from the owner to the man selling ice-creams. It’s a very black moment.
"Darrell now has the biggest role at the football club. He needs to get his team together. Get it moving in the right direction and then build and build a little bit more. The supporters need to see some light.
"First, he needs to get the players together. And then the supporters will come along if they can see things are being done correctly. As look as they see the players giving their all and a team that is progressing, they won’t complain."
Mansfield-born Clarke, who will have to make do without last season's top-scorer Andy Cook following his departure to Mansfield Town, has so far made two signings with Stuart Sinclair and James Clarke following him to the Black Country from Bristol Rovers.
And Bristol-born Graydon, who both played for and managed Rovers during his years with in football, believes it was crucial the boss brought in some players who know how he operates.
Ray continued; "A lot of players have left and a lot of players will come in. But as a manager, your players have to back you up. The signings that have come in clearly believe in Darrell.
"They have had success with him. And they will tell the other players this fella knows what he is talking about and has a clear idea what he wants. He knows their characters and he knows the influence they can have on the group.
"I just want to send him my best wishes, I hope he can have a successful year and build a team that continually moves forward throughout the season."