The 32-year-old centre-back discussed his decision during an appearance on the El camino de Mario podcast, explaining that returning to Bilbao had been his preferred option while considering his future at Manchester City.
“I had it clear. I had opportunities in Turkey with very high figures and others around Europe, but the intention was to return. I grew up here, they gave me the opportunity and they treated me incredibly well,” Laporte said.
His route back to Athletic was complicated by City's asking price when he was considering leaving the Premier League club.
Laporte explained that a move elsewhere in Europe was difficult under those circumstances, leaving Saudi Arabia as the realistic option capable of completing a transfer.
“In my mind, all I wanted was to return to Athletic, but they weren’t in a position to pay a transfer fee like the one City were asking for. The only one that could offer it was Al Nassr and I took the opportunity,” he said.
“They had signed Cristiano, Mané and I said: ‘Why not try a couple of years?’”
Laporte's spell with Al Nassr ultimately preceded his return to Athletic, allowing him to fulfil an ambition he had maintained since leaving the Basque club.
The defender had come through Athletic Club's system and established himself before moving to Manchester City, where he spent several seasons competing at the highest level.
The prospect of returning had therefore been more than a late career decision. Laporte said the idea was already in his mind when he first began considering his departure from City.
His comments also explain why the financial alternatives available to him did not change his preference.
When circumstances finally allowed a return to Athletic, the defender chose the club that had given him his first opportunity to establish himself in professional football.