Smith, whose future remains uncertain despite clinching his second successive title, has called for investment in his squad after automatic entry to the Champions League was secured this week.
The club this week denied reports a decision had been made to ring-fence the new Champions League income and season ticket sales in order to reduce their debt of around 31million.
And, as Johnston attempts to steer Rangers through uncertain times with London-based property developer Andrew Ellis still preparing a buyout, he wants Smith to work alongside him.
The Rangers chairman told the club's official website, www.rangers.co.uk: "This season it has been difficult to try to complete the business plan until such times as we had won the championship and knew if we were directly qualified for the Champions League or not.
"Now that we know that we can try to advise Walter as best we can and he can determine what he does from there. Candidly, Walter has to be part of the solution and not part of the problem. He has a lot of influence and I'm expecting input from him in the next couple of weeks."