Real Madrid are monitoring the situation with El Clasico on the horizon.
Bale missed the 4-1 friendly defeat to Spain in Cardiff on Thursday, after which manager Ryan Giggs said Wales’ talisman was “struggling” to make the trip to Dublin because of muscle fatigue.
The Real Madrid forward must train on Sunday to have any chance of playing at the Aviva Stadium 48 hours later.
But Wales will not take any risks over Bale’s fitness with Real monitoring the situation closely.
The European champions have a hectic eight-day period following the international break.
Real are in LaLiga and Champions League action against Levante and Viktoria Plzen before travelling to Barcelona for El Clasico on October 28.
Wales seem resigned to being without Bale and Ipswich winger Gwion Edwards was drafted in to the senior squad for the first time on Friday.
“It’s going to be a blow being without Gareth,” said midfielder Aaron Ramsey.
“We know how important he is for us as he has scored so many goals.
“But we are looking forward to that test and hopefully we can get back to winning ways.”
Wales were outclassed by Spanish opponents who sent out an ominous Nations League warning to England.
Spain entertain England in Seville on Monday and Ramsey said: “They beat the World Cup runners-up Croatia 6-0 last month, so they are in good form at the moment and we couldn’t live with them at times.
“The manager let us know what he thought of the situation.
“I’m not going to reveal what was said in the dressing room, but he wasn’t happy.”
Sheffield United defender Kieron Freeman has also been drafted into the Wales squad ahead of Dublin with fitness concerns over Ethan Ampadu and Chris Mepham.
Notitngham-born Freeman, 26, has played at under-17, under-19 and under-21 level for Wales but has yet to make an appearance for the senior team.