Evans recently accepted a spot in the Mansfield Under-21 squad for the 2018-19 campaign, but the club announced his sudden death on Friday.
"Mansfield Town football club is deeply saddened to learn of the passing of 18-year-old striker Ryan Evans. Ryan, who was the captain of our Under-18 performance group, died recently at home," read a statement on the club's website.
Academy coach Jamie McGuire added: "We are all desperately sorry to learn of this news and our thoughts and prayers are sent to Ryan's family at this sad time.
"As a player, Ryan was a fantastic leader, always willing to learn and had a never-ending enthusiasm to do the best he could. It was for these reasons, amongst others, that I made him my captain last season. We'll remember him as a smiling young man, with a great energy and charm."
Tributes have been flooding in on social media following the tragic announcement.