Collingwood have suspended star Dane Swan, jeopardising their chances of an AFL top two finish and the midfielder’s hopes of back-to-back Brownlow Medals.

The Magpies backed team rules over star power on Tuesday, banning the in-form 28-year-old for two games for going out drinking on Sunday night.

“The decision was made after the club became aware that Swan had been drinking alcohol six days before next Saturday’s match against the Sydney Swans, a clear breach of club protocol,” the Magpies said in a statement.

“The suspension followed discussions between a number of parties, including the leadership group.”

The club’s players reportedly recently made a pledge to refrain from drinking alcohol for the rest of the season.

According to the AFL website, Swan denied drinking alcohol, admitting he went out on Sunday night but saying he consumed only water.

But he is understood to have been challenged by a teammate over the condition he was in when he arrived at training on Monday.

He subsequently met with coach Nathan Buckley and Magpies players before the ban was issued.

Swan is a three-time Collingwood best and fairest, including in their 2010 premiership year, and won the AFL’s Brownlow Medal last season.

He was among the top few favourites for this year’s award and has been in exceptional form in recent months.

In his past eight matches, Swan has averaged a remarkable 39 disposals and he has also kicked nine goals in the past three rounds.

His absence for clashes with the Swans and Kangaroos, two of the competition’s form sides, could prove crucial for the third-placed Magpies.

A loss to the Swans would leave them two games plus percentage off top spot.

With second-placed Adelaide having a dream draw over the remaining four rounds, it would also mean Collingwood would be unlikely to overtake the Crows.

Assuming they don’t drop out of the top four, that would mean the Magpies would most likely face an interstate trip on the opening weekend of finals.

Swan is the second player this year suspended by the club, with Sharrod Wellingham banned for the first two rounds of the season for drinking while injured.

It comes a day after Western Bulldogs young gun Tom Liberatore was banned by his club for the rest of the year.

Liberatore was found unconscious by the police and with an illicit drug in his possession on the weekend.