The Reds finished in fourth place in the Premier League table and five points ahead of Chelsea FC in the top flight.
The Merseyside outfit were 4-0 winners against Brighton and Hove Albion in their final Premier League fixture.
Liverpool FC lost 3-1 to La Liga giants Real Madrid in the Champions League final in Kiev last month.
The Reds paid the price for a lack of squad depth with Jurgen Klopp’s options limited from the bench following Mohamed Salah’s injury setback.
Liverpool FC have already signed Brazil international Fabinho in a £39m deal from Ligue 1 side AS Monaco in the summer transfer window.
Former Reds striker Fowler believes Liverpool FC need to add more quality players to their squad to be in a position to challenge next term.
“They have a great team, but there needs to be more strength in depth – more options when things go wrong, like they did when Ramos did Mo Salah,” Fowler told the Daily Mirror.
“And he did him, don’t have any doubt about that.”
Liverpool FC have qualified for the Champions League for the second successive season following their fourth-placed finish.
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