Arnold is replacing Ed Woodward on 1 February after the executive vice-chairman stood down following United’s involvement in the controversial plans to form a European Super League.
Kenyon warned that Arnold will have a lot to contend with and that the role is a “tough” position.
“There’ll be a lot of people telling Ed what a failure he’s been,” Kenyon told the BBC’s podcast The Sports Desk. “Most of those people have never been in [his] position. It’s tough, and what Ed oversaw was huge change, because of Sir Alex Ferguson.
“You should never underestimate his [Ferguson’s] role within the club and there was a lot of things that happened when he went. Everyone can be smart after the event, and perhaps they should have spent more time on the preparation post-Alex.
“But it’s hard to understand what you have to fill until the gaps appear. I wish Richard all the very best because it’s a tough job.
“It does have a stature, not just in the Premier League but globally, and we’re in an industry where everyone knows how to do it better than you.”
Arnold isn’t new to the club and has had a hand in day-to-day operations and was widely respected in his role as commercial director. But he also fanned the flames of controversy after boasting to investors about the social media buzz surrounding the signing of Odion Ighalo in 2020.
Kenyon added that as long as Arnold prioritises United’s success on the pitch, he’s confident the club will be heading in the right direction.
“Richard’s years with the club will be beneficial, but he’ll obviously want to stamp his own characteristics on the way going forward.
“He’s done an incredible job on the commercial side of the club. The issue is you can’t forget the core product, and that’s football.”
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