Luis Diaz's return is big for Jurgen Klopp - the Colombian has been the biggest loser from Liverpool's dreadful season

When they reflect on a season in which just about everything that could go wrong, did go wrong, Diaz’s injury, and his subsequent six-month absence, will certainly be viewed by Liverpool as a key moment.

He had been one of the few shining lights in a stuttering start, one of the few players who looked unaffected by the mammoth efforts of the previous campaign. Having hit the ground running following his arrival from Porto in January 2022, Diaz looked ready to go up another level in his first full season on Merseyside.

It was his goal, and a brilliant one at that, which rescued the Reds a point in their first home game of the season against Crystal Palace. Wilfried Zaha’s strike and Darwin Nunez’s red card had left Jurgen Klopp’s side staring down the barrel, but Diaz stepped up for his team, big time.

He got the ball rolling in the 9-0 win over Bournemouth a couple of weeks later too, eventually scoring twice, and then scored the consolation goal in the dreadful Champions League loss to Napoli.

And when Liverpool found themselves behind at home to Brighton in early October, it was Diaz’s half-time arrival which sparked them into life. They drew 3-3 in the end, but they could and should have won following the Colombian’s emergence.

Eight days later came Arsenal, and though Liverpool got off to a(nother) poor start, conceding inside the first minute, Diaz again led the comeback charge, his run and cross setting up Nunez for a well-worked equaliser.

Then came the injury, an awkward challenge with Thomas Partey which left Diaz writhing in agony as he clutched his left knee. On the sideline, Klopp grimaced, fearing the worst. Off went Diaz, and he hasn’t been seen on a pitch since.

The initial diagnosis on Diaz was reassuring, if still disappointing. Fears of an anterior cruciate ligament rupture were dismissed, with Liverpool insisting there was no need for surgery to repair the damaged lateral collateral ligament either. 

“I will come back stronger,” Diaz posted on Instagram on October 12. He would, Liverpool said, be absent until after the World Cup, missing 10 games but returning to training when Klopp’s side travelled to Dubai for a winter training camp in December. 

And so he was. On December 6, both Diaz and the club shared pictures of him, smiling and sprinting, joining in with a session in the sunshine. “Very happy to be back,” he posted. His delight would prove short-lived.

Two days later, it emerged that he had suffered a setback, more discomfort in the left knee, and that would be flying back to the UK for further diagnosis. 

“It’s a proper smash in the face,” Klopp admitted, while many in the medical world questioned the wisdom of Liverpool's initial treatment of the injury. Soon after, the decision was made for Diaz to undergo surgery to repair the lateral collateral ligament.

His partner, Gera Ponce, posted a picture of him in a hospital bed. “Patience and strength are essential,” read the caption. He would be out, Liverpool said, until at least the middle of March.

With Diaz out, and with Diogo Jota also sidelined due to a torn calf muscle, Liverpool chose to bring forward plans to sign a new attacker. In late December, they concluded a deal for PSV star Cody Gakpo, paying an initial £37 million ($46m) to land the Netherlands international.

The team’s form, though, remained infuriatingly mediocre, and having ended 2022 with scrappy victories over Aston Villa and Leicester, the Reds began 2023 with a run of just one win in seven matches, exiting the FA Cup and falling way off the pace in the race for the top four.

A mini-revival in February, featuring wins over Everton, Newcastle and Manchester United, proved a false dawn. Liverpool were battered by old foes Real Madrid in the Champions League, lost in abject fashion to relegation-threatened Bournemouth and are currently on a run of five games without a win in all competitions.

Diaz, as promised, returned to training in March, but his load has been managed carefully, with Liverpool acutely aware of both the sporting and PR cost, should he suffer another setback.

He resumed full training at the end of last month, but was not considered for the games against Manchester City, Chelsea and Arsenal, none of which Liverpool won.

Now, with an eight-day break between fixtures and more than a fortnight of training under his belt, Klopp is ready to involve him in the squad again. He is likely to be on the bench at Elland Road on Monday night. 

Diaz’s return, although unlikely to revive the Reds’ ailing Champions League hopes, is a welcome boost for Klopp, and it will be interesting to see what, if anything, we can learn about Liverpool’s new-look forward line in the closing weeks of the season.

With Sadio Mane gone and Roberto Firmino going, the winds of change are blowing around Anfield. In Diaz, Gakpo and Nunez, Klopp has three new, big-money signings with which to shape a new attacking unit. 

All have shown promise, although it is also fair to say that all have shown a tendency, so far at least, to do their best work from wide on the left. 

Certainly, Klopp will feel he has good options, versatile players in their mid-20s - Mohamed Salah aside - capable of developing into genuine stars with good coaching and a little bit of luck in terms of fitness.

And in the remaining nine games of this campaign, it will be intriguing to see what kind of relationship the likes of Diaz, Gakpo and Nunez can begin to strike up, and how Salah and the out-of-form Jota fit into the equation.

The future for Liverpool starts here.

Of course, Diaz's return should be welcomed, by Klopp, by his team-mates and by supporters.

Pre-injury, he was one of Liverpool's best and most decisive players, his positivity and constant willingness to run with the ball giving the Reds a fresh, exciting dimension in the final third. Even now, after six months on the sidelines, only four Liverpool players have scored more goals this season, and only seven have provided more assists. Diaz still, remarkably, ranks fifth at the club in terms of dribbles attempted and sixth for dribbles completed.

It would be unfair, after such a long absence, to expect miracles immediately, but certainly his presence should help Liverpool as they look for a positive end to an otherwise negative campaign. They have nine Premier League games left, five of them at Anfield and only two against sides currently in the top eight. There should, in theory, be opportunities to make up some ground in the closing weeks.

Unfortunately, it seems unlikely that even an exceptional end to the campaign will be enough to land them Champions League qualification. Newcastle and Manchester United look like they are too far down the road, while even Tottenham, for all their own struggles, are nine points clear at present.

For Diaz, that will sting as much as anyone. Through no fault of his own, a Champions League player looks like he'll be playing Europa League football - or worse - next season.