THE AFL has written to all clubs to remind them of a runner's on-field responsibilities after an incident involving Essendon's Travis Cloke on Saturday night.

It's understood Cloke will not be issued with a formal 'please explain' by the League, although the AFL's general manager of football operations Josh Mahoney has spoken to the Bombers separately regarding his conduct against the Swans.

The former 256-game player, who is now combining his role as Essendon's runner with coaching positions with the club's AFLW program, physically pulled a series of Bombers players away from a scuffle involving their Sydney counterparts on Saturday night.

Cloke did not touch any opposition player, but grabbed at Nick Hind, Jake Stringer, Will Setterfield and Nik Cox to remove them from the altercation.

The AFL has since investigated the incident and has decided to take no action against Cloke, but has spoken to Essendon and written to all 18 clubs to remind them of a runner's responsibilities in such situations.

As part of the letter sent to clubs on Monday, the League has also issued a reminder to inform players not to engage with pitch invaders following a separate incident at the Adelaide Oval on Friday night.

Play was halted during Geelong's win over Adelaide after a member of the public entered the field and came dangerously close to a live contest, before he was brought to the ground by Adelaide's Ben Keays. The pitch invader was then apprehended by security.

The League has reminded clubs and players not to engage in such situations in the future and to be wary of escalating these matters for safety reasons.

The pitch invader was arrested by South Australian police and issued with a three-year ban by the Adelaide Oval, while he also faces a further lengthy suspension by the AFL.