Sier, sidelined by a calf injury for the past month, played basketball last Monday night - but then lied to Magpies officials about his involvement in the game.

The 21-year-old initially told club hierarchy he merely watched the game before later admitting he played under the name 'Phill Inn'.

The Magpies have issued a $5000 fine to Sier and ordered him to perform community service for one night a week for the rest of the year.

Collingwood coach Nathan Buckley says he's more disappointed at Sier's lying than the fact he played basketball.

"(Lying) is clearly more significant to us," Buckley said after Collingwood's 11-goal win against Adelaide on Saturday.

"What is a quite a marginal action, I suppose, has got a lot of coverage.

"But he has been sanctioned. And he understands that what he did was not a great decision."

Buckley expected Sier to return in the Magpies' state league side next weekend.

"He needs to get back on track, train well, play well in the VFL next week and continue to push to be a positive impact on the rest of our 2019 campaign," he said.

"The facts are that there are blokes ahead of Brayden (for AFL selection) at the moment - and the reason they are is because they have performed better than him through the year.

"So Brayden has got a bit of work to make up in a short space of time.

"But we don't know where the twists and turns of the next hopefully five, six weeks for us, we don't know where that is going to take us.

"So we are not going to leave anyone on the side of the road, we need all hands on deck and Brayden will be a part of that."

Australian Associated Press