As one half of the former Leicester Tigers double act who had helped re-establish the Headingley men amongst the elite, Key would have been forgiven for thinking he was all set in life.
But sport is a ruthless business, and Key carried the can for Carnegie’s struggles in the first half of the season, as his long-time colleague, Neil Back, was placed in sole charge.
Key disappeared back to the Midlands, quietly and quickly.
A brief re-emergence with Back to help well-funded Rugby Lions climb the league pyramid did not last very long, and it all led to the former Leciester player retreating so far from the game that he opened a restaurant with his wife.
But he kept his hand in. First, Key took up a consultancy role with an Italian club that should have been just a week but ended up being an entire season.
Then he did a spot of coaching at Cambridge in the fourth tier, but it appeared that his time at the sharper end of the sport had come to an end.
That was until late March when he answered an SOS from up the M1 in Yorkshire.
Rotherham Titans were in distress. Play-off semi-finalists for the second successive time just two seasons earlier, the proud Clifton Lane club were spiralling towards the foot of the Championship table and would be spared relegation to part-time rugby only by London Welsh’s financial implosion.
The Titans needed a lift, and Key needed a new challenge. The two combined were a perfect fit.
“I had been looking for this sort of challenge and opportunity,” said Key, who has thrown himself wholeheartedly into the Titans rebuild.
“I had five really good years out of the game, had three grandchildren, but I was always wanted to carry on in professional coaching. I kept in touch with agents and people in the game throughout that time away and, once I came in here, it was about me being honest with the club and vice versa.
“And, in all honesty, it was a bit like riding a bike again. It’s like I’ve never really been out of the game.”
He describes the situation when he arrived at Rotherham following the dismissal of Justin Burnell in the Spring as a blank sheet of paper.
He oversaw the last two games of the season from afar, getting an idea of how the squad looked, and how he wanted to shape it.
“Since coming in, the key word has been regeneration,” said Key, who has brought in 19 new faces and retained 12 members of last year’s squad.
“We had to rejuvenate the whole programme, with a new management staff, new coaches and two-thirds of a playing squad.
“We’re excited now to put it all into practice.
“I’d been speaking to the board since the end of March as to what they wanted, and then we looked at the areas I felt they needed to strengthen.
“By starting in March we were able to be a little patient with our recruitment.
“I think we’ve put together a good mix of players with experience of playing in the Premiership and the Championship, with those who are coming in from a part-time environment and are hungry to play at this level.”
Five months since taking charge, Key is understandably itching to get going in his first competitive game in charge, which comes tomorrow at Clifton Lane against seasoned Championship operators Nottingham.
Having finished bottom last season the only way is – and has to be – up, for the Titans.
“The club aren’t looking for the Premiership now, or in the immediate future, it’s about delivering a strong and stable team that is competitive in the Championship,” added Key.
“Worst-case scenario for us is the bottom of the table, but I like to think we’ve assembled a 31-man squad that can do more than that.
“It’s not a massive squad so we have to be sensible about how we use our players and how we recover them and how we rotate them throughout the season.
“We won’t be setting big targets because by doing that you can sometimes take your eye off the ball. If we can finish mid-table that will be a pretty good season.”