Yeovil Town captain Lee Collins has died at the age of 32.
Collins began his career at Wolverhampton Wanderers and spent time at Port Vale, Barnsley, Northampton Town, Mansfield Town and Forest Green Rovers before joining Yeovil in 2019.
He played his last game for the club on 6 February against Stockport.
A spokesperson for Avon and Somerset Police said Collins' "sudden" death was not being treated as suspicious and had been referred to the coroner.
Yeovil were due to play Altrincham in the National League on Friday but the game has been postponed.
"All at Yeovil Town Football Club are mourning the loss of club captain Lee Collins," a club statement read.
"Lee sadly passed away yesterday and our thoughts and prayers go out to his family and friends.
"We ask everyone to respect the family's privacy at this time."
BBC Radio Somerset's Yeovil Town commentator Sheridan Robins told BBC Sport: "The main thing that everyone will be feeling is a deep sense of shock.
"He was a real winner. I remember when he first joined the club we were at rock bottom having been relegated to the National League.
"In his interview he was said he wasn't there to make friends, he wanted to win.
"He wore his heart on his sleeve on the pitch and was known for his leadership, he was the epitome of a captain, he did everything he could in that 90 minutes to win the three points."
Collins had been out with injury for large parts of the season, but returned to the bench last week in the 3-1 win over Barnet.
"After the game I spoke to Yeovil manager Darren Sarll and he told me how pleased he was to have Lee back," added Robins.
"He was an old fashioned centre-half and we've not seen him play a lot this season because of injury."
Mansfield Town owner John Radford - for whom Collins played from 2015 to 2017 - tweeted he was "shocked and saddened" to learn of Collins' death.
"A no-nonsense, battling braveheart on the field and a gentleman off it. A man who always gave his all in Stags' colours," Radford added.
Barnsley said they would pay tribute to Collins at Friday's home Championship game against Reading.
Collins was part of the Wolves side, which included Wales keeper Wayne Hennessey and former Bolton midfielder Mark Davies, that reached the semi-finals of the FA Youth Cup in 2005, losing on penalties to a Southampton team featuring Theo Walcott.