Chelsea youngster Jacob Mellis has been sacked by the Blues after the 21-year-old set a smoke grenade off at the club's Cobham training ground on March 2.
Mellis and fellow teammate Billy Clifford, 19, are understood to have brought the grenade from a paintball exhibition, and proceeded to set it off in the reserve team's dressing room.
Fire marshals had to be called as a result of the incident, with club owner Roman Abramovich understood to be furious about the situation.
Mellis had been tipped as a first-team regular in the future, but must now seemingly ply his trade elsewhere.
Clifford, meanwhile, has escaped with just a fine.