The family of former footballer Clarke Carlisle have said they are concerned for his welfare after being unable to contact him.
His wife Carrie said they believed he had last been seen in Manchester city centre at 06:00 BST.
Carlisle, 37, who has previously spoken of his mental health issues, spent six weeks in a psychiatric unit after he was hit by a lorry in 2014.
Lancashire Police said they were "extremely concerned" about him.
A spokeswoman said he was last seen by a family member in Preston's Flag Market at about 14:30 BST on Thursday.
The father of-three, who has tattoos on his arm, was wearing a black jacket, a black T-shirt, blue jeans and Nike trainers.
Carlisle, who remarried earlier this year, played for teams including Burnley, Queens Park Rangers and Leeds United and was also chairman of the Professional Footballers' Association.
He has spoken previously about attempting to take his own life in his 20s and also when he was hit by a lorry near York shortly before Christmas in 2014.
In 2015, he launched a mental health charity called the Clarke Carlisle Foundation for Dual Diagnosis - a condition that has been described as "mental health problems co-occurring with drug or alcohol misuse".
The father-of-three said earlier this summer the worst of his mental health problems were behind him after years of working with psychiatrists, counsellors and family but there were still "bad days".
Carlisle made more than 500 appearances for nine clubs during his 16-year career.
The Preston-born player, who started his career with Blackpool, helped Burnley win promotion to the Premier League in 2009 and also played for Northampton Town.
Det Ch Insp Steve Holgate, from Lancashire Police, said: "We are extremely concerned about Clarke and we would urge anyone who sees him or knows where he is to get in touch with us.
"We would also appeal directly to Clarke himself to contact us if he sees this appeal to let us know he is safe."
Burnley FC tweeted: "Our thoughts are with Clarke Carlisle and his family today. Stay safe Clarke x".
Source: BBC NEWS