St Kilda will be without Ben Long for Friday's semi-final against Richmond after the club's appeal to overturn his one-week suspension was tonight unsuccessful.

The AFL Appeals Board upheld the AFL Tribunal's decision, finding Long guilty of engaging in rough conduct against Bulldogs midfielder Jack Macrae in Saturday's elimination final.

St Kilda appealed the AFL Tribunal's Monday night sanction on the grounds of it being an error of law and that the classification of the offence was "manifestly excessive".

Simon Lethlean said the club was disappointed to have Long unavailable for Friday's semi final.

"We're obviously disappointed with the decision and think we argued a strong case, based on the force of the contact and the resulting impact on the opposition player who played out the entire match."

"We feel for Ben knowing what it means for any player to miss a final and felt it was important to take every opportunity to contest the suspension and provide him with an opportunity to play.

"It is now up to someone to come in and step up in Ben's place. We are confident we have the strength in our squad to do exactly that."

St Kilda will be forced to make at least three changes ahead of Friday night's clash with Richmond after Paddy Ryder (injury) and Jake Carlisle (personal) departed the club's Noosa hub.