Naismith, who retired last year due to injuries, was sitting in the stands without disguise, making his involvement in the spying attempt obvious and raising questions about the lengths teams will go to in high-stakes matches.

The game has heightened stakes, with the outcome potentially determining finals qualification, and the loser risking the historic distinction of missing finals despite winning 15 games.

All-Australian midfielder Adam Treloar, returning from injury and having a strong VFL performance, was not included in the AFL squad to ensure his fitness for potential finals.

Naismith was observed sitting openly with a companion and holding a coffee, highlighting the unusual and somewhat humorous nature of the spying incident.

The Western Bulldogs ejected two Fremantle Dockers staff members from their open training session after they were caught spying on the team ahead of a crucial Sunday match, which has significant finals implications.

The spying incident involved Fremantle's development coaches, including former player Sam Naismith, who was sitting openly in the stands with a companion, making no effort to hide his identity due to his height and recognizable appearance.

Naismith, who retired last year after an injury-ravaged career and has transitioned into coaching, was easily identified because of his large stature of approximately 205cm and his casual, unmasked presence in the stands.

Naismith's conspicuous presence in the stands, dressed in all black and holding a coffee, made the spying attempt obvious, drawing attention to the lengths teams might go to gain strategic advantages in AFL finals.

This incident underscores the fierce competitiveness of AFL finals, where teams are willing to engage in tactics like spying to secure an edge.

The spying episode is reminiscent of past AFL and football spying incidents, including Fremantle's 2015 episode with Port Adelaide and Marcelo Bielsa's well-known spying activities in English football, highlighting the rarity and humor of such events.

The Bulldogs, in good form with four consecutive wins and a healthy squad, responded swiftly by ejecting the spies, emphasizing the importance of fair play and strategic integrity.

Final team line-ups for the match are scheduled to be announced on Friday afternoon, with both teams in strong form heading into the game.