Alvaro Dominguez is considering taking legal action against former club Borussia Monchengladbach for medical negligence.
The former Spanish defender this week announced his retirement at the age of 27 because of severe back problems that had prevented him from playing regularly in the last two years.
Dominguez underwent two back operations in the past 14 months and blames Monchengladbach, the club he joined in 2012 from Atletico Madrid, for not taking his medical condition seriously.
He told Marca newspaper: "I'm considering every option and I'm in the hands of good lawyers in Germany.
"The club never informed me of the seriousness of my injury. I don't need to win a court case, I just want them to recognize that things weren't done right.
"They haven't recognised their mistake, no one has apologised to me. I just hope that by telling my story I can help other sportsmen."
Barcelona goalkeeper Marc Andre ter Stegen sent an inspirational message to Dominguez via his Instagram account.
In every sport an injury is the most frustrating period for an athlete. To end a career early because of this is a tough decision to make. But we must never forget that health is the most important, always! I'm sad to see you hang up your boots so early. You have been a great defender who was always working hard to get better - a true professional! I wish you all the best in your further life and I'm sure you will find something new and special to discover. 💪🏼@a.dominguez18
A photo posted by Marc ter Stegen (@mterstegen1) on
Dominguez, who made 120 appearances for Atletico, joined Monchengladbach in 2012 on a five-year contract.
He made 103 appearances in all competitions for Monchengladbach, his last coming on Nov. 7, 2015, in a home Bundesliga draw against Ingoldstadt.
"Since February 2015 I had strong pain that worsened every day," he said. "I had an MRI and they [club] told me not to worry, that it would go away.
"Before a Hertha game in May, I was unable to walk. The doctor injected me painkillers and told me that it could happen to anyone.
"I trusted him but I wasn't even able to get on the plane so I went home.
"I had some therapy but I was later asked to play again and I did.
"I couldn't move after that and the [club] doctor told me that what I need was a holiday."
Dominguez had tests done in Madrid that summer which revealed a serious back problem.
"I was surprised," he said. "The club never informed me about the seriousness of the injury. I returned to Gladbach.
"I showed them the medical reports and they told me to start preseason, that they would treat me."
He played 10 games at the start of the 2015-16 campaign under a lot of pain.
"As soon as I finished playing, I would go home and get into bed as it was the only thing that alleviated the pain," Dominguez said. "I was a professional on the pitch but off it I was an invalid.
"I went to see a specialist Wohlfahrt Muller and as soon as he saw the results, he told me I needed surgery right away." Dominguez claims Monchengladbach did not consider his condition serious.
"I met the sporting director, the coach, the doctor and the [club] vice president and explained to them that what I had was very serious and that I could end up in a wheelchair if I continued to play," he said.
"I had three herniated lumbar disks. They asked me to postpone the operation until Christmas and I refused as I couldn't even walk. I had the operation."
Dominguez underwent a second lower spine operation earlier this year knowing it would mean an end to his playing career but would offer him a better quality of life.
"I knew that no player had ever returned to play like that," he said. "I still have pain when I wake up and when I go to bed but it's not so intense."
The Madrid-born Dominguez, who made two appearances for Spain in 2012, feels let down by the Bundesliga side.
"Above all there has been a lack of humanity," he said."Through all this, the club wasn't even paying me because under German law, after six weeks out injured, you only receive 20 percent of your wages which is paid by your private insurance.
"That didn't even cover my medical costs. The club only offered to pay 30 percent of the treatments.
"I had the feeling that after giving everything to the club and going through so much pain when they needed me most, they had abandoned me."