By Gabriel Tan in Manlia
The Lions, who booked their place in the semi-finals after finishing top of Group B ahead of Malaysia, Indonesia and Laos, take on Philippines in Saturday's first leg at the Rizal Memorial Stadium.
Isa, who had an impressive season with Malaysia Super League outfit LIONSXII, was expected to play a key role in the Singapore engine room, but had to settle for a place on the bench as coach Radojko Avramovic initially opted for Hariss Harun and Mustafic Fahrudin as his central-midfield partnership.
However, an injury to Hariss has since opened the door for the 26-year-old, who made his first appearance in this year's edition of Southeast Asia's premier international tournament as a substitute in their final group game against the Laotians, which ended in a 4-3 victory to the Lions.
Given the physical battle Singapore are likely to be faced with against Philippines, Isa is set to get his first start of the tournament on Saturday, an opportunity he is looking to grab with both hands.
"I'm really looking forward to it," he told ESPNSTAR.com.
"I waited till the last game of the group stage and I got my first action in the last 20 minutes.
"I'm hungry for more and I'm looking forward to every minute of the game tomorrow [Saturday]."
Speaking at Friday's pre-match press conference, Avramovic reiterated his faith that the likes of Isa would be able to step in for Hariss and Shi Jiayi, who has temporarily left the Singapore camp due to a personal matter.
Nonetheless, the humble anchorman, who was present when his side last won the tournament in 2007, insists it is not just him who is capable of rising to the occasion.
"It's great that the coach believes not only in me, but everyone on the bench waiting to step up," he added.
"Especially in a short tournament like this, where you are bound to get suspensions and injuries, the 22 players that were selected are ready to step in at anytime.
"I'm glad the coach has put his faith in us."
After years of domination over Philippines, the Lions have not had the best run of form against Saturday's opponents recently, falling to a 2-0 defeat at the Jurong West Stadium back in September before losing to them 1-0 in Cebu just last month.
Still, the combative midfielder believes plenty has changed since both sides last met and he is hoping his side can draw from their strong showings in Group A, where victories over Malaysia and Laos sandwiched a controversial loss to the Indonesians.
"Those [the defeats to Philippines earlier in the year] were just friendlies and the coach was still experimenting with the team," Isa explained. "Now it's a different ball game.
"There's a lot at stake here for the two nations given it's the semi-finals. Philippines have come a long way in football - we know that - but we're going to take our game a step higher to compete with them.
"We've had a good campaign so far with only one loss. Philippines will pose a different threat but we're looking forward to it. I think if we can get a good result here, it will really put us one step closer to the final.
"Overall, the mood in the camp is very good and we're just looking forward to the first leg."
In the other semi-final, Malaysia entertain Thailand at the Bukit Jalil National Stadium on Sunday, before heading to Bangkok's Suphachalasai Stadium for next Thursday's return encounter.