The 23-year-old will miss Saturday's final league game of the season at Crewe to ensure a slight groin strain heels completely.
Cardiff have already booked their place in the play-off lottery by finishing in the four qualifying places in Division Two.
Depending on the Gresty Road result, and the others involving the three play-off sides, Cardiff could finish as high as third or as low as sixth.
A string of poor results in the past month ended hopes of an automatic promotion spot, but Gabbidon believes last Saturday's home draw with champions Wigan showed Cardiff are finding form just at the right time.
And the Wales international says it is vital the players enter the play-off believing they can win every game.
 It's been a long hard season and it'll be very disappointing to miss out again Danny Gabbidon |
"You can't go into those games thinking we're not in good form," Gabbidon told BBC Sport.
"You've got to be confident. You've got to look at the last game and take it from there.
"We didn't get the win against Wigan, but we played fairly well and it was a massive improvement from the games before. We'll just take things on from there.
"Anything can happen in the play-offs - we might be in a bit of poor form there, but it might all come right at the right time.
"So we're looking forward to it, we can't wait for it to start."
Gabbidon had to sit out all of Cardiff's games from early November until early April because of a mystery back injury.
He was forced to leave the field mid-way through the first half against Wigan, raising fears that the troublesome injury had returned.
But the injury has responded well to treatment this week, and Gabbidon, who tasted play-off heartache against Stoke last season, says the play-offs cannot come soon enough.
"I've been raring to go. I've been a long time out and it's been frustrating," he said.
| The play-offs are far more important than a friendly in America Danny Gabbidon on missing Wales game |
"I'm just glad to be back now and hopefully I can help to get promotion.
"It's been a long hard season and it'll be very disappointing to miss out again now at this vital time."
Gabbidon's long injury lay-off also meant he missed out on two of Wales' Euro 2004 qualifying games.
Wales play a friendly in the United States of America on Monday, 26 May - a day after the Division Two play-off final at Cardiff's Millennium Stadium.
But Gabbidon admits he will be more than happy to miss the chance to add to his four international caps if it means Cardiff will be in that final.
"I've missed the last few trips, so it would be nice to go away with Wales," he said.
"But the play-offs are far more important than a friendly in America. My mind will be on Cardiff and doing the business for them."