The Reds attempted to sign the Guinea international in a big-money deal from Bundesliga giants RB Leipzig last summer.
The German club refused to sell Keita to Liverpool FC but the Reds managed to reach a £48m agreement to sign the box-to-box midfielder in the 2018 summer transfer window.
Keita helped RB Leipzig to qualify for the Champions League for the first time in their history following a return of eight goals and nine assists in 2016-17.
The African star has netted five times and has made five assists in 23 games in the German top flight this season.
Keita has helped RB Leipzig reach the Europa League quarter-finals following a return of one assist in four outings.
Liverpool FC were without captain Jordan Henderson in the middle of the park for their 2-1 victory at Manchester City in the second leg of their Champions League quarter-final.
Former Reds captain Thompson believes Keita will be a great addition to the Liverpool FC team.
“They’ve already strengthened with the signing of [Naby] Keita from Leipzig. I think he is absolutely terrific,” Thompson told Sky Sports.
“I was watching him against just last week in the Europa League and my goodness, this guy will probably give us what we’ve lacked.
“In that three behind the front three – he gives you goals, he gives you assists, he gives you energy and he’s a nasty little character.
“There is only James Milner who will really put his foot in and I think this guy could be a real sensation in the Premier League.”
Liverpool FC are in third place in the Premier League table and on course to finish in the top four for the second successive seasons under Jurgen Klopp.
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