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So after a good few weeks of speculation, it's finally official: Luis Suarez has left Liverpool to sign for Barcelona, as confirmed by BBC Sport, for a fee of about £75 million.

As Liverpool fans across the world start to come to terms with the news that one of their greatest-ever players has left after leading the Reds to within a whisker of the Premier League title last season, they might be feeling just a little apprehensive about the coming 2014/15 campaign.

And who could blame them? After all, it's not just any ordinary forward who has left Anfield: Suarez left at the peak of his powers, having matured from a profligate finisher to a world-class forward, setting scoring records in the Premier League last season despite missing his first five league games of the season.

Yet—unbelievable as it may be—it's not all doom and gloom for the Reds. Sure, it will be a tough ask replacing the 30-plus goals Suarez now guarantees a season, but there should be other priorities in Brendan Rodgers' mind even now.

He must focus on strengthening his defence.

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Defence a Red Achilles' Heel

By the end of the 2013/14 Premier League season, when Manchester City had finally usurped Liverpool as champions-elect, it was too little, too late to realize where Liverpool had lost the title.

Perhaps Steven Gerrard will forever shoulder much of the blame for his fatal slip against Chelsea, when he mistakenly put Demba Ba through on goal. And perhaps it was the throwing away of a three-goal lead at Selhurst Park that confirmed their fate.

But throughout the whole campaign, it was Liverpool's defence that let them down. A total of 50 goals conceded—the second highest among the top eight, just a solitary goal behind sixth-placed Tottenham Hotspur—said it all about a shaky defensive unit that frequently had to rely on an admittedly all-star attack to bail them out.

Suarez's departure will add more pressure to his ex-strike partners to come close to the astonishing 101-goal haul last season, but it will also place the spotlight on a leaky defence that has to get better.

There are always two sides to the same coin and two contrasting ways to look at a trend: Namely, that Liverpool showed both strength in character and mentality to secure comebacks and outscore their opponents by one goal to get the three points—but equally, Rodgers' back four weren't exactly a reassuring presence when they needed to be.

Of course, it didn't help that due to injury, Rodgers was deprived of his first-choice back four for most of the season—though that was the opportunity that Jon Flanagan took with both hands to resurrect his career at Anfield—but the time has come now to address these problems.

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Upgrades Are Needed

It seems strange to see Liverpool building bright young midfield and forward lines, especially with the signing of Emre Can and the blossoming of Raheem Sterling, on a foundation provided by an increasingly erratic Glen Johnson, an inconsistent Martin Skrtel, a hesitant Daniel Agger and a perpetually injured Jose Enrique.

Though Johnson seemed to have rediscovered his form at times toward the end of the season, it is telling that he has yet to sign a contract extension. As things stand, he will be a free agent next summer.

As prolific as Skrtel was last season, scoring seven league goals in 36 games, he was also responsible for four own goals, and his concentration and leadership have yet to truly convince.

Vice-captain Agger is a curious case. As one of the Reds’ most loyal servants in the group, he seems to have lost the faith of Rodgers, with Mamadou Sakho often preferred as the starting left-sided center back, and he is even linked with a summer exit from Liverpool, according to Spanish newspaper Mundo Deportivo (h/t Vaishali Bhardwaj of Metro).

Finally, Enrique's brand of physical and brazen football doesn't fit in well with Rodgers' preference for intelligent tactical play; even Flanagan's displays seemed to have worked better in his system.

Given the high-profile links with Southampton's Dejan Lovren, per Gary Jones of the Daily Star, it seems evident that Liverpool have identified center back as a priority position, but the reality is that upgrades are needed all across the back four.

And we haven't yet touched on the hotly debated position that is goalkeeper.

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An Unlikely Smokescreen Would Be Nice

Yet for all of the strengthening that Liverpool's defence need, the rumor market is still in a frenzy linking the Reds with a forward to replace the goals of Suarez.

Now that Alexis Sanchez, previously a candidate either to play with Suarez at Anfield or to replace him as part of the deal taking the Uruguayan to Camp Nou, has joined Arsenal, the seemingly most adequate successor has slipped out of Rodgers' grasp.

Cue the rumors linking the Reds with a move for Swansea City's Wilfried Bony, via Sam Cunningham of the Daily Mail, and the apparently imminent double deal for Divock Origi and Lazar Markovic, via BBC Sport's Ben Smith.

All well and good, except they seem to hint that the club are preoccupied with filling the Suarez-shaped void up front and neglecting the obvious issues at the back.

Besides Lovren, Liverpool have not been seriously linked with any central defender, while an on-again, off-again approach for Sevilla's Alberto Moreno seems to be their only lead in the full-back areas.

Which leaves arguably more than half of all the defensive positions in need of upgrading, if we include Simon Mignolet's position between the Anfield posts.

Shave away Suarez's 31 league goals from Liverpool's total tally, and they would have scored just one fewer than Chelsea. Contrast Liverpool's 50 goals conceded with Manchester City's 37 and Chelsea's 27—even Arsenal's 41—and we arrive at the root of the Reds' failure to win the league.

There are big issues to address at the back for Brendan Rodgers. Liverpool fans should be hoping that the incessant and never-ending striker rumors are but a smokescreen for the real revolution that needs to take place in defence.

Otherwise—Suarez's goals or not—they'll be in for a rough ride.

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