As a huge (maybe even bigger than that) Def Leppard fan I’m more than just a little concerned right now.

It only seems like yesterday that I was basking in the glory of the band’s best record for 20 years and a triumphant headline show at Download 2009.

Leppard were back and back in a big, big way. Songs From The Sparkle Lounge proved to be a triumphant return to the band’s 80s heyday and a co-headline UK arena tour alongside Whitesnake wowed audiences the length and breadth of Britain.

Then there was Donington this time last year. The scene of Leppard’s emotional 1986 comeback once again reverberated to the old classics and the new standards.

But less than a year down the line and Sheffield’s finest are in the midst of a 12-month hiatus. Or could it be longer? The evidence suggests as much.

At least three of the Lepps now have successful side projects which could easily distract them from their day jobs well into 2011.

Phil Collen is a key member of retro three-piece Man Raze and Joe Elliott has thrown himself into Mott The Hoople covers band the Down N Outz big time. Then came the news that Vivian Campbell is a member of the all-new star-studded supergroup trading under the Thin Lizzy name. They’re touring the UK in January and could roll on throughout next year.

Now even without any outside tasks to complete Leppard have never been the most prolific when it comes to producing new records.

Even when the band has demanded their full-time attention it’s taken the true perfectionists of pop metal ages to deliver their new record.

And even without touring commitments and festival slots these boys work at a painstaking pace.

So with all of the above keeping Phil, Joe and Viv busy for the rest of 2010 could this be the beginning of the end for my favourite band of all time?

I happened to watch an interview with Joe the other day when he admitted all bands come to the end of the road at some point or another. Previously Leppard have survived everything thrown at them and retained the core of their original line-up longer than most. But Elliott has obviously prepared for the unthinkable happening.

At the same time rumours abound across the rock world that Joe, for one, feels Leppard could have run its course. Those close to him have indicated his passion is for the Down N Outz and their glam rock future rather than his multi-million selling band’s glorious past.

That would certainly explain Campbell’s bold decision to hook up with Scott Gorham and Lizzy. And it might explain why Collen is throwing so much time and energy into Man Raze.

It might even get to the bottom of why Leppard cut short the final leg of their Songs From The Sparkle Lounge tour with a series of lucrative US dates still to play.

In a recent interview with their local evening newspaper, the Sheffield Star, Elliott and Rock Savage sought to allay any fears about the premature demise of Leppard by promising a renewed attack on the rock world and an all-encompassing box set.

But for all their talk the evidence, as I say, is pretty damning. And Leppard fans everywhere should be very worried indeed.