It is one of the greatest mysteries of football - whatever happened to Fernando Torres? The striker was probably the most feared in the world during his pomp with Liverpool between 2007 and 2010. The Spaniard was a combination of pace and power - custom made for the Premier League. But now, at Chelsea, he is being deemed as simply "not good enough".

Those were the words of Sky Sports' Gary Neville directed at all of Chelsea's strikers after Torres' lacklustre performance in last Monday's forgettable 0-0 draw at Arsenal, where the failure to score ensured a striker from the Stamford Bridge club did not hit the back of the net away from home in the Premier League in the entirety of 2013. It is a remarkable statistic but one which epitomises Torres' loss of form over the past three-to-four years. It is a fall from grace which, ahead of Sunday's latest reunion with Liverpool, means he has yet to score against his former club in six previous attempts having not been involved in the 2012 FA Cup final.

Torres took the Premier League by storm when arriving at Liverpool from Atletico Madrid in the summer of 2007 in a £26.5million deal as a 24-year-old. He went on to score 24 goals from 33 top-flight appearances in a spectacular debut 2007/08 campaign. That season ended in him scoring the winner for Spain in the final of Euro 2008. He had also become the first Liverpool player to score more than 20 league goals in a season since Robbie Fowler in 1995/96. Likewise, he hit 33 goals in all club competitions to surpass the record set by Manchester United's Ruud van Nistelrooy and become the most prolific foreign debutant in English football. It was form which led Liverpool captain Steven Gerrard to say in the December of 2007: "Fernando is getting a lot of praise at the moment and rightly so, because the way he has settled into English football has been amazing and the way he has played is frightening. It can be difficult for players from abroad to settle into English football but, at the moment, Fernando looks like he has been playing here for years."

Tellingly, though, that number of 33 appearances would be the highest total Torres would play in a single Premier League season for Liverpool. He had suffered from a groin problem in the October of 2007/08 and then a hamstring injury in the February but that was just a sign of things to come.

Hamstring injuries plagued Torres into the 2008/09 campaign. He experienced one in each month of the August, October and November. Torres said of those injuries in his 2009 book, 'El Nino, My Story': "It was a real hammer blow. The first time it happens you think it is normal and you keep going. The second time, you stop, you take more care and you start to ask yourself why it happened. The third time, you stop properly, you start to investigate the underlying causes and work as hard as you can to make sure it never happens again. That was even more important in my case, because it was my hamstring that was causing me problems - the muscle I live by, the one that gives you acceleration and speed."

An ankle injury also saw Torres miss two Premier League games in the February to March of 2008/09 but it was the hamstring injuries which were of greater concern given the way they affect a player's pace. This was particularly relevant for Torres, who has always relied upon his ability to turn on the afterburners - knocking the ball past a defender followed by a burst of speed - above the accuracy of his shooting in order to create his goalscoring opportunities. This is emphasised by the statistics on Torres' shooting accuracy. The best of his first four seasons in England came in 2009/10 when his shooting was at an accuracy of 50.79 per cent. But that is still poor in comparison with the current likes of Romelu Lukaku, Sergio Aguero and the new darling of The Kop, Luis Suarez, who all boast shooting accuracy levels of more than 60%.

Torres' developing hamstring injuries were also a worry given he had suffered just one muscle injury in his previous six years at Atletico. It created an argument that perhaps the changes in Torres' physique - the slight shifts in the ever-so-finely balanced physiology and metabolism of professional sportsmen combined with playing in the increased physical nature of the Premier League - meant his body was creaking as he grew into his mid-Twenties under the very attributes which made him such a dangerous player. It was an eerily familiar story to former Liverpool striker Michael Owen.

Despite Torres' injury problems, Liverpool still enjoyed their best campaign in Premier League history in 2008/09, finishing second and just four points behind champions Manchester United. But conflicting with many people's memories of that campaign, which included the Gerrard-Torres attacking partnership, this was achieved with their star striker experiencing his worst campaign of the three full seasons he spent at Anfield. In 2008/09, Torres scored 14 Premier League goals from 24 appearances but that averaged at a goal only every 123.79 minutes, his shooting accuracy was down at 43.06% and his shots-to-goals conversion rate (excluding blocked shots) was less than 20%.

In 2009/10, Torres suffered an abdominal strain which saw him miss more than a month between the November and December but, positively, he had seemingly overcome his hamstring problems. This, though, seemed to be at a cost. He was to endure a recurring cartilage problem in his right knee which required two operations - firstly in the January and then again in the April. Did the knee injury come as a result of trying to protect his hamstrings? The April operation ended Torres' season.

Torres was statistically still at his most lethal in front of goal for Liverpool in 2009/10. In just 22 Premier League appearances, he scored 18 goals. He averaged a goal every 95.28 minutes, had that shooting accuracy of more than 50% and had his best shots-to-goals conversion rate of 28.57%. But, and it is a big but, that excellent form came almost completely before the first knee operation in the January. After returning from that surgery, he scored just six Premier League goals in the remainder of 2009/10. Likewise, Torres struggled after the second knee operation in the April. He recovered in time to go to the World Cup that summer but, surrounded by rumours of concern he had rushed back in order to be a part of Spain's squad for a World Cup in which they were strong favourites to win, he failed to score in seven appearances at the tournament. To make matters worse, he suffered another groin injury in the final victory over Holland which required three weeks of rehabilitation.

Amid Torres' knee operations, Liverpool had also been having a bad time. They finished seventh in the league, made an early exit from the UEFA Champions League and manager Rafa Benitez left at the end of the campaign. This was all engulfed by the off-field ill-feeling from fans towards the club's American owners, Tom Hicks and George Gillett, and a status in multi-million pounds' worth of debt. It led to snowballing speculation of Torres' discontent.

Having recovered from his World Cup final injury, Torres was fit for the start of the 2010/11 Premier League season and he came on as a 74th-minute substitute in the opener against Arsenal. He would go on to make 23 league appearances for Liverpool, of which 22 were starts. However, he scored only nine times and looked a different player to before his knee injuries while also appearing too frustrated by Liverpool's on and off-field struggles. It would prove to be his final campaign at Anfield. Fenway Sports Group completed their takeover of Liverpool in the October of 2010 and doomed Benitez successor Roy Hodgson would be replaced by Kenny Dalglish in the January of 2011 but Torres still ultimately requested a transfer and made his record-breaking £50m move to Chelsea that same January.



Torres' forcing of the transfer caused outrage among millions of Liverpool fans who were appalled by a player who had always spoken of his commitment to the club and appreciation of their values. With all that in mind, Liverpool fans felt betrayed when Torres left and directed the sort of fury in his direction which would damage the self-belief of any hardened soul, let alone one who was widely assumed to not have the greatest self-confidence. Could this have led to his loss of form? Torres was, and is, a player who needs to be at peak mental fitness to be at his best. It is considered he needs to be loved.

Aged 27 when he joined Chelsea, Torres has infamously gone on to continue to struggle. He scored just once - against West Ham United in April - in the second half of that 2010/11 season. Perhaps that level of scrutiny he found himself under as the Premier League's most expensive transfer combined with the fury from Liverpool fans had led to the yips? Torres ended 2010/11 with his overall statistics, including both his time at Liverpool and Chelsea, at their lowest since he arrived in England. He made more Premier League appearances (37) than in any of the previous three seasons but he scored just 10 times, averaged a goal only every 265.8 minutes and his shots-to-goal conversion rate was at just 13.33%. That dip in form has of course also proved to be far from a blip, as a player who will turn 30 years old at the end of January 2014 has scored just 17 goals in 64 Premier League starts for Chelsea. Last season, he scored 23 goals for Chelsea but only eight of those came in the Premier League.

Interestingly, Torres' muscular injuries, although not completely a thing of the past, have become less frequent at Chelsea. This could be due to a training programme which, to the eye at least, appears to have increased his muscle bulk. But this could also be due to intentionally becoming less dynamic in his style of play, adopting a more static approach, in order to protect his muscles. It could also be argued he has simply become less mobile since those knee operations in 2010, which in turn has led to the decrease in his goalscoring threat.

Torres has had his moments at Chelsea. That is even somewhat of an understatement when considering he has been a part of squads who have won the Champions League, FA Cup and Europa League. At the same time, he and his team-mates have also had the challenge of having to adapt to the changing tactics of five different managers, including interim boss Benitez. In the current season, there have been flashes of Jose Mourinho rediscovering the player of old, against Schalke in the Champions League and Manchester City in the Premier League in October. Likewise, Torres did finish with the Golden Boot as top scorer at Euro 2012, again netting in the final as Spain defended their continental title with a 4-0 hammering of Italy. But they have been anomalies and he is unquestionably not the same threat as the player who arrived in England in 2007.

All of Torres' injuries, particularly those in his hamstrings, have taken their toll, ebbing away at his natural attributes and self-confidence. But the manner in which he enjoyed his best season, statistically, in 2009/10 having overcome his hamstring-plagued 2008/09 suggests his muscular injuries have not been the main root of his downfall. The argument that his loss of confidence after leaving Liverpool also has merit but his collapse in the first half of the 2010/11 season, before he left Anfield, would also suggest that is only a minor variable.

The true point at which Torres' goalscoring brilliance was shattered appears to clearly trace back to the double knee operation of 2010. Knees are the second heart of any footballer - once they are gone, it is the beginning of the end. Torres had scored a phenomenal 50 Premier League goals in 72 games up to the first knee operation in January 2010. Since then, he has scored a pitiful 32 Premier League goals in 125 appearances. Sadly for Torres, and for all those who watched in wonder at his once world class goalscoring vitality, force of nature and brilliance, the overall statistics tell the entire story. As he approaches the wrong side of 30, there will be no way back to the golden days of his former self.