The home side finished first with 70 points in the Montenegrin top flight, while the visitors won the Welsh Premier League with 92 points.
Match preview
The last time the hosts prevailed as winners against an opponent that had scored at least three goals was in April 2023, when they beat Buducnost 4-3.
Last term, Decic scored three or more goals in the top flight on seven occasions, but they only won by three clear goals three times.
Realistically, if they are to progress then they will have to prevent their opponents from scoring, and to their credit they did keep 16 clean sheets in their 36 league matches.
However, manager Milorad Pekovic's side have not won any of their five games in UEFA competitions and are still seeking their first victory in European football.
In fairness to Decic, they are competing in their first ever Champions League campaign so perhaps it should be expected for them to encounter difficulties.
Domestically, the hosts scored 55 goals and conceded 27 times in the top flight last season, and these records made them the division's second best offensive and best defensive team.
As for the visitors, they won their league title last term having scored 117 goals and conceded 18, records which made them the best offensive and defensive side in the Welsh First League.
In fact, The New Saints went unbeaten in both the regular season and their championship playoff group, and they ended the campaign 33 points clear of second-placed Connah's Quay Nomads.
However, it should be noted that they have failed to win their last five two-legged European ties.
This includes their matchup against Viktoria Plzen in the 2021-22 Conference League third qualifying round, which they drew 5-5 on aggregate despite having taken a 4-2 first leg lead.
Craig Harrison has been in charge of The New Saints since August 2022, but this is his second time as boss after he previously coached the side from December 2011 until 2017.
Decic Champions League form:
L
The New Saints Champions League form:
W
Team News
The hosts will likely start Bojan Matic in the forward line, and they will need him to replicate his goalscoring feats from last season if they are to overcome the odds.
However, given Decic need to score a minimum of three goals, it would not be a surprise to see Ian Puleio start out wide, especially as he was subbed on in the 46th minute of the first leg.
As for the visitors, Brad Young is certain to start given he scored twice in the reverse fixture.
Elsewhere, Harrison will likely field a similar starting XI that could see the likes of Daniel Davies continue at left-back, and captain Daniel Redmond take charge of midfield once again.
Decic possible starting lineup:
Nikic; Dresaj, Milic, Ujkaj, Malesevic; Chagas, Bozanovic; Puleio, Kajevic, Masovic; Matic
The New Saints possible starting lineup:
Roberts; Daniels, Pask, Bodenham, Davies; Clark, Redmond, Smith; Brobbel, Young, Williams
We say: Decic 1-3 The New Saints
Although Decic performed impressively over the course of last season, it is difficult to see how they can overcome the 3-0 deficit.