Speaking to the club's official website, Sheffield United manger Chris Wilder said: "At the top of the pitch we have one of the country's hottest properties from Liverpool and for him to sign permanent here is fantastic for everyone concerned."
"He has been our number one target and I am delighted to have secured his services. He's a natural goalscorer. He finishes from any aspect, whether it is in the air or whether it's spectacular goals, free-kicks or off his shin - he has a lovely habit of scoring goals."
Rhian Brewster officially joined Sheffield Utd on Friday for a club-record fee of £23.5 million, putting pen to paper on a five-year contract.
The Reds have succeeded in inserting a buy-back clause active for three years in the deal for the 20-year-old, as well as a 15 per cent sell-on clause.
