Jonathan de Guzman appeared to be in a really good place in 2014 after playing at the World Cup for a Dutch side that would eventually finish 3rd.De Guzman started in the play-off against Brazil - a 3-0 win - a fitting end to a two-year spell that had seen him shine for Swansea City.He'd helped deliver the League Cup to Wales the previous year and had certainly built a reputation for himself as a fine midfielder over his two-year loan spell.Those two years, coupled with a decent World Cup, meant De Guzman was ready to take a step up in 2014.He'd get one, too, signing a four-year contract with a Napoli side managed by Rafa Benitez.Things started well as he scored a 95th-minute winner on his debut and November saw the Dutchman bag a hattrick against Young Boys in the Europa League.But then De Guzman appeared to simply fall off the map - his name is one that has disappeared over recent years and as it turns out, there's a sad story as to why.Thanks to a brilliant Twitter thread that details the story with the help of quotes from a recent interview with De Guzman, we know that his downturn in fortune started in March 2015.You can check out the thread below:

De Guzman complained to Napoli's club doctor about a painful lump in his stomach and Alfonso De Nicola, the doctor in question, simply puts him on a diet and tells him to rest.

When that inevitably didn't work, Benitez told De Guzman to see another professional but was denied - he saw De Nicola and no one else.

The player claims he was at about 50% of his fitness because of the issue but Napoli believed he was faking it.

"They did not believe I had any trouble," he told Volksrant. "I could walk, but not turn on or shoot completely. They thought I made it up.

"That was said to me so often that I started to doubt the signals of my own body. It was sick."

Napoli wanted to sell him but he refused, leading to an altercation with technical director Cristiano Giuntoli that saw De Guzman punched in the face.

Instead, Napoli decided to let the player rot: "You're not going anywhere, you stay here, you're dead here." 

De Guzman says he spent four months training on his own, only really able to walk - no teammates helped him, although he understands why as the club would have punished them.

He eventually does get to see a new doctor, provided by the Dutch national team, who diagnoses De Guzman with a sports hernia - only for Napoli to deny him the operation.

It wasn't until he was loaned to Carpi in the summer of 2016 that he was able to have that operation.

Still unfit, he turned down a move to China and instead signed for Eintracht Frankfurt in 2017 - helping the team to the German Cup last season.

The story does have a somewhat happy ending there, but it's undeniable that Napoli have cost him years of his career. For a player who was doing so well, that simply must be heartbreaking.