West Coast Eagles star Willie Rioli has been provisionally suspended in relation to an ASADA test last month.

The goalsneak has been suspended under assertion of “urine substitution”, according to AFL integrity chief Andrew Dillon.

The test was taken on August 20, two days after West Coast’s Round 22 loss to Richmond at the MCG.

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“The provisional suspension will last until the matter is determined,” Dillon said at a press conference in Melbourne this afternoon.

The maximum ban Rioli is facing is four years.

The Eagles released a statement this afternoon saying the club had been made aware that Rioli was the subject of an ASADA and AFL investigation.

“The club is extremely disappointed that one of our players has been provisionally suspended while a matter is being investigated and it will comply fully and openly with ASADA and the AFL through the process,” it reads.

“The club is fully committed to supporting Willie during what is a personally distressing time.

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“Our primary concern is Willie’s health and welfare.

“As this is an on-going investigation the club, its staff and players can make no further comment until the investigation is completed.

“The West Coast Eagles fully supports the AFL and ASADA in its ideal of our game being drug free.”

Rioli, 24, was notified last night after arriving in Victoria ahead of West Coast’s semi-final against Geelong and has been withdrawn from the Eagles squad.

Jack Petruccelle has flown to Melbourne as cover for Rioli.

Rioli has kicked 18 goals in 14 games this season and was an integral part of last season’s rise to the premiership.