Real Madrid forward Bale has been out of action since sustaining a hamstring injury in Wales's goalless draw with Estonia on 9 September (AEST), missing his club's past 13 matches.
The 32-year-old's three appearances for the Dragons this season is as many as he has managed in all competitions for Madrid since returning from a loan stint with Tottenham Hotspur.
Despite his latest spell on the sidelines, Madrid boss Carlo Ancelotti gave his blessing for Bale to link up with Robert Page's side for games against Belarus and Belgium.
Bale has declared himself ready for Sunday's (AEDT) clash with Belarus, which would make him just the second player after Chris Gunter (106) to reach a century of caps for Wales.
"I'm not in peak condition like I was before, but I've worked as hard as ever to get back in time," Bale said at a pre-match news conference.
"I'm as fit as I can be but the match fitness is not there. All I can do is give my best. I'm not sure I'll be able to play the whole game, but I'm here to give 100 per cent.
"Reaching 100 caps will be an incredible achievement. It's nice for me and my family, but the most important thing is the game and not the occasion.
"Hopefully I can enjoy it after the game, which is [a] must-win for us. For the time being it's easy to wander back but all focus needs to be on the game."
Bale has played in two European championships with Wales, reaching the semi-finals in 2016 and Round of 16 earlier this year, but he has yet to have a taste of the FIFA World Cup.
The Dragons are already assured of a spot in March's play-offs, but are now aiming to finish above Czech Republic in second place in Group E to secure a home tie.
For Bale, a winner of 13 trophies at club level, including four UEFA Champions Leagues, reaching what would be a first FIFA World Cup since 1958 for Wales is next on his wishlist.
"We've got to try to push and qualify for the World Cup now. It's an important game for us to win," he said.
"We've all [got to] give it our 100 per cent best, never have any regrets and always fight to the end. We have a chance to do it now and we have to try and capitalise on it."
Asked if he would swap one of his UEFA Champions League triumphs to qualify for the FIFA World Cup, Bale said: "It's difficult to say, but we'll fight until the death to achieve that.
"We'll fight as hard as we can in these last couple of games."
Bale's importance to Wales since making his first appearance against Trinidad and Tobago in May 2006 cannot be understated.
Wales has won 48 and drawn 14 of the previous 99 games with Bale in the side for a win rate of 48.5 per cent, which drops to 27.7 per cent in the 47 games he has not played in.
The Madrid man has scored 36 goals for the Dragons, 20 of those coming during Chris Coleman's tenure between 2012 and 2017.
He also scored once under Brian Flynn, two under John Toshack, three during the late Gary Speed's reign, three under current incumbent Page and seven with Ryan Giggs in charge.
Perhaps unsurprisingly, given Wales's run to the UEFA Euro semi-finals, 2016 was Bale's most prolific calendar year with seven strikes, followed by the five he managed in 2015 and 2018.
Bale has faced 44 different opponents across his 15-year international career, with Finland the side he has come up against most often (six times), while Andorra, Belarus and China (three goals against each) are his favourite opponents.
Speaking alongside Bale on Friday, interim head coach Page said: "Looking back at [UEFA] Euro 2016 when I was a supporter was tremendous and being part of his journey, he's just as enthusiastic today as he was then.
"It's been a pleasure to work with him and be a part of his journey. Humble is the right word. He's a prankster among the group. He's jovial and wears the armband with pride.
"He's absolutely a superstar and I do think a lot of youngsters look up to him and the way he takes care of himself. He's been an inspiration to a lot of children."