Smith announced in May that he's sitting out the 2019 season due to personal reasons, and he confirmed the fine Saturday on Instagram.
The NFL's collective bargaining agreement mandates the fine. The defender can avoid future penalties by filing retirement paperwork with the league. Jacksonville can then place him on the reserve/retired list, freeing up Smith's roster spot and removing his salary-cap hit.
In his May announcement, Smith didn't reveal whether he's planning to retire. However, the veteran did note he wants to end his career with the Jaguars.
The 28-year-old signed a four-year, $45-million extension with the Jaguars in October 2017. He earned a Pro Bowl selection that season but wasn't as effective in 2018.