The 31-year-old St Finbarr’s man, who made his SFC debut 12 years ago, played his last game for the county against Mayo in last summer’s extra-time All-Ireland qualifier defeat to Mayo.
Former captain and two-time All-Star Shields had returned to the panel last year having been released back to his club in May 2016.
Shields, a three-time Munster medallist, 2007 U21 All-Ireland winner and three-time Division 1 winner, told the42.ie of his news yesterday, explaining that demands away from the field were mounting as well as an increasing number of injuries in recent seasons.
“This wasn’t an immediate decision, it was something I thought about for a while. I’m really going to miss it but I think this is the right time to step away. I’ve had a lot going on in the background with work commitments and family commitments. It’s made it very hard to juggle all three.
“The frustrating thing for me over the last few years is I’ve had a lot of injuries. I’ve been getting a lot of knocks throughout the season which set me back and I found I was chasing my fitness.
“I’ve had problems with my groin, I had Gilmore’s groin on both sides. I had operations on that and then the two winters there when I was getting operations, I was coming back late.
“It’s always hard when you’re trying to train and come back into the National League late. Your fitness probably isn’t where it should be and unfortunately for me, I picked up a few knocks and setbacks along the way.
“I missed out on 2016 so I lost that year and last year was a year when I was probably coming towards the end.
“When you lose one year and come back another year, it’s hard to pick it up again.
“When you’re younger there’s no doubt about it that it’s easier. You’re in college and have the freedom of time to recover. I’ve found the last couple of years that I haven’t been able to fully recover. It was always a battle to get right.”
Shields had suggested to McCarthy that he was going to step away for 2018.
“I’d a nice chat with Ronan. A couple of months back I told him where I was at and I said I’d meet him soon.
“I met him the other day and just told him my thoughts. I’m delighted he got the job, he’s a really decent man.”