Making their debut in Asia's premier club competition in this year's expanded format as runners-up of last season's Singapore Premier League, Tampines are still looking for their first points as they head into the third matchday in Group H.
Meanwhile, Jeonbuk entered the 2021 Champions League after a double-winning season in South Korea where they were victorious in both the K League 1 and Korean FA Cup last year. They have also been regulars in ACL since the turn of the century, lifting the trophy in 2006 and 2016.
As the first club from the city-state to compete in the group stages in over a decade, Tampines were considered outsiders in their pool but have put on decent displays thus far to make Singaporean football proud. On their ACL debut, the Stags did not allow themselves to be intimidated by former champions Gamba Osaka in a 2-0 defeat.
Buoyed by that close fight against Gamba, Tampines were unfortunate to concede a narrow 1-0 loss to fellow Southeast Asian side Chiangrai United in their second outing. Thailand attacker Sivakorn Tiatrakul slotted home the winner in the 87th minute after the SPL side had struck the woodwork twice earlier in the game.
Jeonbuk, meanwhile, needed a penalty from Gustavo to defeat 2019 Thai League 1 champions Chiangrai 2-1 in their opener before playing out an unconvincing 2-2 draw against Gamba, who are currently struggling to avoid relegation back home in the J1 League.
So, do Tampines have what it takes to pull off an upset against Jeonbuk on Thursday?
It's going to be a right slog for coach Gavin Lee and his wards even to salvage a point out of the clash as they throw down the gauntlet against one of the strongest teams in Asia.
But a game of football can be won by a single moment of brilliance, and Tampines do boast a few players who can come up with the goods when needed. Serbian star Zehrudin Mehmedovic is one such star and is ably partnered by Japanese Kyoga Nakamura in the midfield.
19-year-old Ryaan Sanizal has been a revelation in the opening fixtures and has partnered both 37-year-old Baihakki Khaizan and 43-year-old Daniel Bennett at the centre of the defence with great panache.
There could be other factors that could come into play as well. The conditions at the Uzbek capital of Tashkent where the temperature soars to over 40 degrees during the day, seems to be taking a big toll on Jeonbuk players in the previous games.
Manager Kim Sang-sik was forced to substitute his captain Hong Jeong-ho at half time against Gamba, while several players from the South Korean side were also struggling with the heat on Monday.
Tampines' performances in the game against Gamba and the narrow loss to Chiangrai signal a growing belief in the camp.
Had their finishing department been a little more efficient, the Singaporean outfit would have been in a different position going into Thursday's game.
If they are to make amends, there is no better time to do so than in one of the biggest games the competition is offering the Stags.