After years of being Manchester City's primary challenger in England, Liverpool took a step back last season. The Reds finished fifth in the Premier League, a fortunate position considering the Reds were eighth in mid-February.

This was from the Liverpool team that won the Premier League in 19-20 or even the team that finished second in the league and captured the FA and League Cups in 21-22.

Liverpool's biggest weakness during the 2022-23 season was its central midfield. Fabinho looked out of his depth, Jordan Henderson is not the same player he once was, and Thiago endured an injury-riddled campaign. The Reds struggled with depth in this area during the year, and with center mids Naby Keita, James Milner, and Alex Oxlade-Chamberlain all leaving the club over the summer, Liverpool must replenish in the transfer market.

Also leaving the club at the end of the season was Roberto Firmino. Firmino never became the elite goal scorer that fans in Liverpool expected after he joined from Hoffenheim in 2015, but that didn't stop him from becoming one of the most impactful center forwards in European football. His off-ball running, passing, and pressing made him invaluable to Liverpool's domestic and European successes.

Firmino, even in his diminished role this past season, supplied 11 goals and four assists in the EPL while starting about a third of Liverpool's league matches. His 15 goal contributions ranked second on the team — a total that will be sorely missed with the Brazilian attacker playing elsewhere next season. His departure leaves the Reds with plenty of wide attackers by no true center forward outside of Darwin Nunez.

One final area of concern is center back. Virgil van Dijk easily had his worst season in a Liverpool uniform, and Ibrahima Konate was the only other defender to make an impact out of the trio of Joe Gomez and Joel Matip.

Given this wide variety of concerns, here are four players Liverpool must sign this summer to return to Premier League contention.

Amine Gouiri (ST), Rennes

Using FBref's Scouting Report comparison tool, the advanced statistics show that no European player is more similar to Roberto Firmino than Rennes striker Amine Gouiri.

Like Firmino, Gouiri is an off-the-ball workhorse who is a menace in the counter-press. The Frenchman also has three consecutive seasons with 18+ goal contributions in Ligue 1.

Khephren Thuram (CM), OGC Nice

With the attacking-minded Alexis Mac Allister already in the fold, Liverpool needs a defensive option alongside the Argentinian. Khephren Thuram played as a central midfielder on a Nice side that allowed the second-fewest goals in Ligue 1 this past season.

With the ball at his feet, the 22-year-old Frenchman excels at progressing the ball forward off the dribble, taking on and beating opponents — not unlike Yaya Toure.

Manu Kone (CDM), Borussia Monchengladbach

If Liverpool wants to go even more defensively-minded than Khephren Thuram, then Manu Kone is a great box-to-box option. Also a 22-year-old Frenchman, Kone led Monchengladbach in tackles per match during the 22-23 season and fouls committed.

Offensively, Kone is like Thuram in that he frequently progresses the ball through dribbling, though he is less likely to make an impact in the final third.

Levi Colwill (CB), Chelsea

Colwill has been impressive during loan spells at Huddersfield Town and Brighton & Hove Albion, winning aerial duels at a high rate and looking comfortable with the ball at his feet. He will be a tough player to pry away from Chelsea.