Origi signed for Liverpool for a fee that could rise to £10 million, and the 19-year-old has been loaned back to Lille to continue his development and get regular game time.
He caught the eye of many fans at the World Cup, particularly for the impact he made on games for Belgium - which included a winning goal against Russia during the group stages.
Mignolet, who was also part of the Belgium squad, got a first hand look at Origi in Brazil, and the told the official Liverpool website: "He is a very exciting player and a huge prospect, and he will have one more year with Lille.
"I'm sure that after that he'll play very well for Liverpool. He's got a huge future ahead of him. I wish him all the best this season and hopefully we'll see him soon.
"When we arrived with the Belgium squad, nobody had really heard about him to be honest. He played at Lille but had never been called up for the full squad, just the U21s.
"Because Christian Benteke was unfortunately injured, we needed a striker - he came in and from the first day in training he showed his ability. In the games, he showed what he was all about."
On the face of things, Origi has made a pretty good start to the season in France, having scored the winner for Lille from the penalty spot against Caen, their second outing of the season.
He is also going to get the opportunity to play in the Champions League this season and is likely to get both valuable game time, and big game experience prior to his arrival at Liverpool.
Some will have argued that Liverpool could have done with Origi this season as the Reds continue to search for a new striker before the transfer window closes on September 1.