O’Kelly, Dean Smith’s former No.2, returned to the club to assist Sadler in the interim last month following the dismissal of Michael Flynn.
However, Sadler has confirmed the experienced O'Kelly won't return to a role full-time, and instead just remain as a mentor.
The new Saddlers boss added he is on conversations with potential members of his backroom staff - and is hopeful of making appointments soon.
The former Blues, Shrewsbury and Saddlers defender said: “Rich is a friend and mentor and a person I can continually pick the phone up to and who will pop down to the training ground.
“He said to me a couple of weeks ago ‘any time rice pudding is on the menu he will be there’ – it’s on every day from here on in!
“Rich is a friend, but won’t be joining full-time. There are ongoing conversations, two or three we are talking to, that will be soon.”
Sadler’s first task as Walsall boss was to release a number of the current squad, with players such as Liam Kinsella, who has enjoyed a long association with the Saddlers’, leaving the club.
The new Walsall boss revealed how he is working closely with the club’s board, and Trivela Group’s vice-president of global football, Matt Jordan, to identify “quality new signings”, as he looks to build his squad for the new campaign.
“I will work really, really closely with Matt Jordan, who fulfils that technical director role for Trivela Group – not in name but we’re working really closely together.
“I’ll bring an assistant and first-team coach in and then the rest of the structure will stay the same.”