"Obviously it would be stupid to take any risks, and I won't be doing that," he said.
Just three games short of playing his 25th and blazer game for Wairarapa-Bush, Isaac was named as a midfield back in this year's Heartland championship squad but his injury problems have kept him sidelined, much to his disappointment and that of head coach Mark Rutene.
"Tapaga is one of those guys you can rely on to give 100 per cent each time he goes out there. He's an excellent team man in every regard," Rutene said. "He could have been very handy for us, no doubt about that."
A major highlight for Isaac over the past few seasons was captaining Greytown to their Tui Cup title two seasons ago and asked if he had any regrets his quick answer was losing to Gladstone in this year's semis.
"I really thought we were capable of going the whole way and to lose that one was pretty gutting."
Whatever the future holds for Isaac, however, the chances are he won't be entirely lost to rugby.
Refereeing and coaching hold some appeal to him.
"A lot of people have helped me along the way and I'd like to give something back," he said.