Giovanni van Bronckhorst’s side, who finished runners-up to Celtic last season, entered the competition in the third qualifying round and they begin with a tricky away test before the return fixture at Ibrox the following week.
Should the Ibrox side overcome Karel Geraerts’ men over the two-legged tie then they’ll progress to the play-off stage where they’ll compete for a place among Europe’s elite clubs.
The Light Blues return to European action for the first time since losing the Europa League Final on penalties to Eintracht Frankfurt in Seville.
They warmed up for the match by beating Livingston 2-1 at the Tony Macaroni Arena on Saturday, with goals from Scott Arfield and James Tavernier cancelling out Joel Nouble’s early opener.
Brussels-based side Union Saint-Gilloise finished second in the Jupiler Pro League last season, 12 months after sealing a return to the top-flight for the first time in 49 years.
Rangers will train at OH Leuven’ stadium this evening and two players - Rabbi Matondo and Ridvan Yilmaz - who missed Saturday’s win over Livingston will take part in the session.
We’ve gathered all the information you need on the match and how to watch it below…
Where is the game taking place & what time does the match kick-off?
Who: Royale Union Saint-Gilloise vs Rangers
What: UEFA Champions League (Third qualifying round)
Where: King Power at Den Dreef Stadion, Leuven
When: Tuesday, August 2nd – kick-off 7.45pm (UK time)
How to watch on TV – Is there a live stream?
Yes, the game will be broadcast live on Premier Sports 1. Coverage begins at 7.15pm - 30 minutes before kick-off. Existing subscribers can stream the match via the Premier Player. New customers can purchase a monthly pass from £9.99.
A pay-per-view option will be available via RangersTV.
What are the latest match odds?
UNION SAINT-GILLOISE 17/10 | DRAW 12/5 | RANGERS 31/20
The Belgian side are narrow favourites to record a first-leg advantage. Dante Vanzier and Dennis Eckert are 11/2 joint-favourites to open the scoring, Fashion Sakala is favourite to score first for the visitors.
*Odds from BET365 correct at time of writing*
Who are the match officials?
Bosnian referee Ifran Peljto has been selected by UEFA to take charge of the game. He will be assisted by Davor Beljo (Bosnia) and Senad Ibrismbegovic (Bosnia), with Marco Fritz (Germany) named as the Video Assistant Referee. Milos Gigovic (Bosnia) is the fourth official.
What’s the team news ahead of Union Saint-Gilloise vs Rangers?
Rangers manager Giovanni van Bronckhorst revealed he has injury doubts to contend with but confirmed newest signing Ridvan Yilmaz and Welsh winger Rabbi Matondo have travelled with the squad to Belgium.
Turkish defender Yilmaz, who arrived in Glasgow from Istanbul at the weekend following the completion of paperwork to finalise his transfer from Besiktas, could make his debut, while Matondo has recovered from a minor injury picked up towards the end of pre-season.
Winger Ryan Kent has been ruled OUT due to an ankle knock sustained in the closing stages of Saturday’s game and was sighted with the travelling part on Monday.
Striker Alfredo Morelos will be given the chance to prove his fitness ahead of kick-off as he closes in on a return to action. The Colombian hasn’t played since March after requiring surgery on a thigh injury, but he was spotted taking part in an open training session at Ibrox last week.
There is no place in the 23-man European squad for centre-back Nikola Katic, while Jack Simpson, Charlie McCann, Stephen Kelly and recently-departed winger Glenn Middleton were also left out.
Kemar Roofe, Ianis Hagi and Filip Helander remain on the sidelines and highly-rated youngsters Alex Lowry, Adam Devine and Leon King were on the ‘B’ standby list.
Speaking in his pre-match press conference, van Bronckhorst said: “We trained yesterday and had another session this morning. Rabbi trained with the team as did Ridvan, but we still have some injury doubts so we need to see whose fit.
“Both can can travel with us this afternoon. I have a lot of respect for Union Saint-Gilloise and you can see a clear style of play. It may be an unfamiliar name around Europe but they deserve to be in Europe with their style of play.”
Former Portsmouth defender Christian Burgess could line up for the visitors, while fellow Englishmen Marcel Lewis (ex-Chelsea youth) and Ross Sykes (ex-Accrington Stanley) are also expected to feature.
Key dangerman Dante Vanzier has the potential to cause the Gers defence problems, while on loan Brighton striker Simon Adingra will aim to start his first Champions League match.
Travelling squad: McGregor (GK), McCrorie (GK), McLaughlin (GK), Tavernier, Yilmaz, Goldson, Souttar, Davies, Barisic, Lundstram, Jack, Davis, Kamara, Sands, Sakala, Arfield, Colak, Lawrence, Matondo, Morelos, Wright, Tillman