Leyton Orient manager Justin Edinburgh has died aged 49 after suffering a cardiac arrest.
He was taken to hospital on Monday, two days after attending the Champions League final between his former club Tottenham and Liverpool.
Leyton Orient announced his death in a statement on Saturday.
We are deeply saddened and shocked to hear of the passing of Justin Edinburgh.— Tottenham Hotspur (@SpursOfficial) June 8, 2019
Our heartfelt condolences and thoughts go out to his family and friends at this terribly difficult time as well as everyone that worked alongside Justin at Leyton Orient. pic.twitter.com/rFRZZYNuLa
"We are completely heartbroken by this tragedy," said Orient chairman Nigel Travis.
"All our thoughts and love are with the Edinburgh family and we know from the messages that have flooded into the club over the last week that the wider football world will share our sentiments."
Edinburgh had just guided Orient to promotion back to the Football League after taking over in November 2017 as the club began an extensive rebuild.
"The success that Justin brought to Leyton Orient was incredible, but more importantly the impact he had on us all as a winner and a wonderful, inspirational human being will be his legacy and will stay with us forever," said Travis.
Fans gathered at the Breyer Group Stadium on Sunday morning to pay tribute to Edinburgh.
Messages of condolence, flowers and shirts have been left and Leyton Orient have said the stadium will be open between 11am and 3pm to allow fans to pay their respects.
Edinburgh began his playing career at Southend, winning promotion from the fourth tier, before joining Tottenham in 1990.
He made 215 appearances for the club and was part of their FA Cup and League Cup-winning teams in 1991 and 1999 respectively.
Tottenham tweeted: "We are deeply saddened and shocked to hear of the passing of Justin Edinburgh.
"Our heartfelt condolences and thoughts go out to his family and friends at this terribly difficult time as well as everyone that worked alongside Justin at Leyton Orient."
Edinburgh also spent three years at Portsmouth before returning to his native Essex to end his playing career as player-manager of Billericay Town.
After spells with Fisher Athletic, Grays Athletic, Woking and Rushden & Diamonds, Edinburgh took charge of Newport County in 2011 and guided them to promotion back to the Football League after a 25-year absence.
Edinburgh spent over three years with the Welsh club before joining Gillingham in 2015, and a brief spell with Northampton Town followed.
Leyton Orient appointed Edinburgh in November 2017. He won 45 of his 82 games in charge, clinching promotion from the National League and a return to Wembley for the FA Trophy final.
The League Managers Association paid tribute to Edinburgh, with chairman Howard Wilkinson calling him a "true professional".
Wilkinson said: "A hard-working man who became successful as a player at the highest level of the game and turned his love of football into a life-long career as a coach and as a manager.
"At a time when he should be celebrating the success of his team and preparing for the rewards of league football next season, he has been lost to the game and to his community too soon."
Edinburgh is survived by his wife Kerri and their children Charlie and Cydnie.
Leyton Orient pay tribute
Orient captain Jobi McAnuff said: "Totally and utterly devastated. You were so much more than a manager to me. Just doesn't feel real coming so soon after sharing some of my happiest moments with you. My thoughts, love and prayers go to the family at this truly terrible time. RIP Justin."
Josh Coulson: "Heartbroken right now. Devastated. Gaffer you made me fall back in love with the game. And to be a champion with you will stay with me forever. Rest well up there."
Craig Clay: "Absolutely heartbroken. You was genuinely more than a gaffer to me and I'll be forever grateful for what you've done for me. Rest in peace Justin."
Danny Happe: "Absolutely heartbroken on the news with gaffer my love goes out to all of his loved ones. Can't thank you you enough for everything you have done for me, it's been a pleasure. To a great man & manager. RIP."
Macauley Bonne: "There are no words to describe the loss of our gaffer, our leader & inspiration. First & foremost, my deepest condolences to Justin's family. He brought us all together - we're eternally grateful for everything you've done."
Former Orient chairman Barry Hearn: "Words fall short of the sadness this news brings. A lovely man who achieved so much for Leyton Orient. He shall not be forgotten."
Tottenham team-mates 'shocked' and 'saddened'
I’m numb, so sad to hear about my friend #JustinEdinburgh we played together 29 years ago @SUFCRootsHall gaining promotion from L2. Then 6 years at @SpursOfficial my thoughts at this time are with Kerry and the kids and the family. Rest in peace my friend #RIPJustin— Dean Austin (@dean316austin) June 8, 2019
Gary Lineker: "Deeply saddened to hear that Justin Edinburgh has passed away. He was an excellent coach and a terrific fullback who was a delight to share a dressing room with and have as a teammate. Thoughts are with his family. #RipJustin."
Ledley King: "I can't believe this saw Justin last week and he was in great shape and full of life. He was genuinely one of the nicest guys you could meet. Thoughts and prayers to his family. RIP mate."
David Ginola: "Justin Edinburgh... deeply shocked, deeply saddened. RIP my friend, I shall miss you."
Darren Anderton: "Can't believe it.. such sad news about Justin. It's not fair. One of the greatest guys you could ever
wish to meet. When you were around him, you just laughed and smiled constantly. RIP mate."
Glenn Hoddle: "Devastated to hear the very sad and tragic news regarding Justin. My thoughts and prayers are with his family and friends at this extremely difficult time."