The 18-year-old midfielder, who joined from Internacional last summer, has already spent time out on loan at SJK in Finland earlier this term - where he thrived after being given his first taste of competitive first-team football.
There, he made eight league appearances and scored twice, as well as registering five assists as they secured a first-ever title and he's since impressed Jürgen Klopp in training at Melwood since October, taking part in a number of behind-closed-doors friendlies and playing for Michael Beale's Under-21s.
Now, Allan is set to spend the next six months in Belgium with the Canaries - who are on course for a midtable finish just a year after winning the Second Division title.
Allan to garner experience out in Belgium for the rest of the season
He becomes the 11th Liverpool player out on a temporary deal, with Klopp having taken the chance to bring several young players back in order to ease the current injury crisis depleting the options available to him currently.
But with the Brazilian teenager having not yet received his work permit to be able to ply his trade in England, it has been decided that Allan should be sent out on loan to further help improve his game.
Sint-Truiden currently sit 10th in Belgium's top-flight - though they're just five points clear of the relegation zone and five points away from qualifying for the Championship play-offs.
They face giants Anderlecht, Standard Liege, Club Brugge and Lokeren all inside the next six weeks - meaning Allan will earn yet more valuable experience should he play a prominent role from the offset.
With the Academy staff at Liverpool having high hopes for Allan, it is expected that he will challenge for a place in Klopp's first-team once he returns in the summer, provided his work visa complications are straightened out.