Sir Alex Ferguson's daughter-in-law and grandson were described as "seriously ill" today after they were involved in a road crash.
Nadine Ferguson, 30, who is separated from Sir Alex's son Darren, was airlifted to hospital in Manchester following the collision near her home in Cheshire yesterday morning.
The couple's 10-year-old son and six-year-old daughter, named in reports as Charlie and Grace Ferguson, were taken by road ambulance to Leighton Hospital in Crewe.
The boy was later transferred to Alder Hey Children's Hospital in Liverpool.
Police have not said what injuries the family suffered.
A spokeswoman for Cheshire Police said: "The young boy was taken to Alder Hey where he is in a very serious but stable condition.
"The six-year-old girl was treated for minor injuries at Leighton Hospital.
"Their mother was taken to Wythenshawe Hospital where her condition is serious."
Mrs Ferguson's black Vauxhall Corsa was in collision with a Ford Fiesta on Trap Street, Lower Withington, Macclesfield, at around 8.25am yesterday.
She was separated from Peterborough United boss Darren, 37, in 2006 after four years of marriage.
Last year he admitted assaulting his wife during a row on the driveway of his parents' home and was fined £1,500.
Macclesfield Magistrates' Court heard Ferguson raised his leg and struck Nadine's stomach.
Manchester United boss Sir Alex last night gave away no sign of his family's worries as he watched his side cruise into the Champions League Final.
United beat Arsenal 3-1 in the semi-final second leg at the Emirates stadium.
It was reported the Fiesta driver, believed to be a 17-year-old boy, was taken to hospital with leg injuries and was in a stable condition.
A local resident, Lynda Syers, 60, told The Sun: "The car was surrounded by paramedics and firemen. I could see the driver in the passenger seat sobbing her eyes out.
"She was cradling her young daughter and trying to comfort her, but they were both completely distraught.
"They were watching a paramedic apply a bandage to the boy's head in an ambulance. He was dazed. I heard his mum saying over and over, 'My poor babies'. She was clearly in shock."