Nacewa had own doubts
Toulon tests convinced him his return to Leinster was justified
Isa Nacewa has revealed for the first time how 'The Prodigal Son' was compromised by doubt on his return to Leinster.
When the New Zealander officially announced his decision to retire from rugby in March 2013, the then 30-year-old went with the promise that he would only ever contemplate coming back in the blue of Leinster.
It left a legacy of brilliance that was immediately jeopardised when Leinster convinced Nacewa that what amounted to a two-year sabbatical should end last summer.
The last thing the faithful fans wanted to see was a deteriorated one-time great bowing to the march of time.
Comebacks are rarely king in the unforgiving environment of professional sport.
"I wouldn't have come back if I knew wasn't able to compete," he said.
There was always the expectation that Nacewa could quickly cut it in the League. The Champions Cup Pool of Death was another kettle of 'piranha'.
"There's a very big difference between the levels of PRO12 and The Champions Cup.
"That was quite eye-opening coming up against the best in the world in Toulon," said the 33 year-old.
There was also the twin Premiership threats from Wasps and Bath.
"I had almost built a bubble in my head to think, 'I'm not good enough or I'm not fast enough or I'm not big enough.'
"As soon as I finished one of those Toulon games and knew I could compete, it sealed the deal that it was the right decision to come back."
The Leinster Nacewa returned to has not been the dominant, electric force of old through Leo Cullen's first year in charge.
The club has changed. So has he.
"I think you have doubts, but you learn to manage them," said the former Auckland Blues mental skills coach.
"Because I had been out of the game from actually physically playing it, sometimes those thoughts creep back in.
"A light bulb goes on in your head to remind you you can do it and you've just got to get on with it.
"I wouldn't have had those thoughts through the last couple of years of my first time here.
"But, they were definitely there when I came back."
There can be no regrets for Leinster's captain from 20 caps and all but five minutes of his four European Cup matches.
Four more matches would take him to the PRO12 League final and his 150th appearance for Leinster.
Not bad for an older man.