The 20-year-old Brazilian spent the 2016/17 campaign in the Bundesliga. Making 16 apperances in all competitions, Allan enjoyed a solid season in Germany in the middle of the park.
Allan de Souza set for another loan spell
He will be sent out on loan again next season as Liverpool await an English work permit in the future. It's another chance for Allan to continue to gather sufficient experience before he returns to Merseyside and tries to stake a claim in Jürgen Klopp's Premier League plans.
Reports emerged this week that Hertha sent Allan back to Merseyside after being unsure whether to extend his current deal or not. However, the Liverpool Echo believe that the club remain the favourites to secure Allan for another year.
Negotiations between the two clubs are ongoing with Liverpool eager to secure 'penalty fees' based on the number of games the Brazilian plays. That marks a precautionary measure from the club over his first-team opportunities, having made just eight starts last season.
Liverpool keen to ensure Allan gets experience
Liverpool will want to ensure he gets the most experience under his belt as possible. Hertha's qualification to the Europa League group stages will likely bring about more chances for him to do just that. However, any deal between the two parties will depend on Hertha's summer acquisitions.
Arne Maier, a young talent within Hertha's current ranks plays the same position as Allan and could scupper his appearances while other additions are expected in the transfer window.
A number of other clubs across Europe have expressed an interest in signing Allan this summer. Signing for Liverpool from Internacional in 2015, the Brazilian has now spent time at SJK and Sint-Truidense.
There remains a strong belief on Merseyside that Allan has a very bright future at the club and another loan spell with regular first-team appearances will only do him good when a work permit is granted.