Cliftonville lost 2-1 to FK Auda from Latvia last Wednesday evening at Solitude and it left the Belfast side with a mountain to climb in the return game in Riga.
Jim Magilton's Reds were downed on home soil as goals from Abiodun Ogunniyi and Abdulrahman Taiwo either side of debutant Luke Conlan's equaliser settled the first leg clash.
Auda v Cliftonville hasn't been chosen for live television coverage in the UK.
Auda v Cliftonville is scheduled for a 16:00 BST kick-off on Wednesday 31st July at the Skonto Stadions in Riga, Latvia.
The clash at Solitude a week ago was the first and only meeting between these clubs, with Auda coming out on top 2-1 in a tight encounter.
Auda wins | 1 |
Draw | 0 |
Cliftonville wins | 0 |
*H2H stats refer to all competitions
The opportunistic Abiodun Ogunniyi put the Latvians on their way to a good night in Belfast last week and it was Taiwo that sealed the win with a calm finish in the second period.
Following a good win for Zeljkovic's side, with no new injury concerns, it's expected that the same starting line-up in the second leg will aim to stop the visiting Reds claiming what would be only their sixth European victory in 42 attempts.
Goalscorer Conlan was one of a number of Cliftonville players making their debuts last week, alongside Michael Newberry and Ruaidhri Donnelly.
Ryan Curran also made a long-awaited return from injury for Magilton's side.