West Ham star Kurt Zouma and his family were left terrified after their home was raided by an armed gang who stole £100,000 in cash and jewellery.
The gang are said to have broken into the defender's home on Saturday while he was at home with his family.
Zouma was unavailable for West Ham's home game against Crystal Palace on Sunday following the incident, The Sun reported.
The club initially claimed that Zouma could not play due to "personal reasons".
A source told the newspaper: “This was an extremely worrying attack and left Kurt and his family traumatised.
“They were an aggressive and organised gang – and the house was completely ransacked.
“Kurt and the family were put through an horrific ordeal, and are still struggling to speak about what happened.
“Everyone at the club immediately knew it was incredibly serious – as he would not have missed a game otherwise."
They added: “The player’s family are too scared to stay at the house – and have already talked of needing to move.
“Kurt is a family man and in shock. He is worried about protecting his family.”
West Ham on Monday confirmed that they were offering a £25,000 reward for information leading to the gang's capture.
The club said in a statement: “West Ham United has offered a £25,000 reward for information leading to the arrest and successful prosecution of burglars who broke into defender Kurt Zouma’s home on the eve of the Club’s Premier League fixture against Crystal Palace this weekend.
“Kurt’s home was broken into on Saturday while all his family were in the house, leaving everyone present extremely distressed.
"While thankfully no one was harmed, it was a traumatic experience for the West Ham United defender, his wife and their young family.
“The burglars took items of significant value and of huge personal and sentimental importance to the family.
“The West Ham United family continue to offer Kurt’s family their full support.”
Zouma has four children with his wife Sandra, who he first met when they were teenagers in Lyon.
West Ham’s Joint Chairman David Sullivan said: "To have someone break into your home is a terrifying experience and I hope this reward will help bring the individuals to justice and prevent others from going through a similar ordeal.”
A spokesperson for Essex Police said: “We were called shortly after 11.50pm on Saturday 2 December to reports of a burglary in west Essex.
“It was reported suspects had gained entry to an address, before taking items including jewellery and watches.
“Our investigation into this incident is continuing."
Anyone with relevant information is urged to email firstname.lastname@example.org. Information will then be shared with the police.
Police are urging those with information to contact them by calling 101, quoting incident number 1306 of 1 December.