Celtic will have a new manager in charge for the 2016-17 campaign.
Ronny Deila is in charge of Celtic at the moment, but the Norwegian will step down from the managerial role at the end of the season.
A new manager is yet to be appointed, although one suspects that it will be sorted in the coming weeks.
Former Celtic goalkeeper Bonner believes that the Scottish Premiership outfit need to spend big money in the summer transfer window.
The former Republic of Ireland international has said that Celtic need to spend as much as £30m in order to become competitive.
"For me, there are two things," Bonner told The Scottish Sun. "The first is that whoever comes in, the club’s leaders have to give him £20m to £30m to bring in those quality players the fans are desperate for.
“Or they could bring in a manager who is going to be on a budget and is not going to get those sort of players and will have to develop his own players. I think the fans want the opposite. I believe they want someone to come in and make a real impact."
Celtic have won the Scottish Premiership title yet again this season, but their overall campaign has not been great.
The Bhoys failed to progress to the group stage of the Champions League for the second successive season.
The main priority for the Celtic during the 2016-17 campaign would be to qualify for the group stage of Europe’s premier club competition.