Former Germany international Michael Ballack and his family suffered an irreparable loss following the death of his son Emilio Ballack.
The 18-year-old was killed in a quad bike incident in the holiday destination Troia, south of Lisbon in the early hours of Thursday morning.
Firefighters and police officers rushed to the incident but he died at the scene with psychologists also on hand to provide support to the family.
Portuguese media reports said the teenager had been riding on an uneven piece of land near the Ballack family home, when the bike rolled backwards and fell on top of him.
Michael Ballack joined Chelsea in 2006 after four years with Bayern Munich, where he won three Bundesliga titles and three German Cups.
While at Stamford Bridge the midfielder won the Premier League, the League Cup and three FA Cups and also played in Chelsea’s 2008 Champions League final defeat on penalties to Manchester United.
He left Chelsea in 2010 to re-join former club Bayer Leverkusen, before retiring two years later.
Chelsea sent their condolences to the Ballack family, tweeting: “Everybody associated with Chelsea Football Club is shocked and saddened to learn of the death of Emilio Ballack at the terribly young age of 18.
“All our thoughts are with his father Michael and his family at this sad time.”
Emilio was born in 2002 to Michael’s then-girlfriend Simone Lambe. The former Germany captain has two more sons from his relationship with Lambe, born in 2001 and 2005.