COLLINGWOOD star Steele Sidebottom suffered a ruptured testicle at training and it's unclear when he will return.

The gun midfielder received an accidental kick to the groin during the Magpies' session on Wednesday and was scheduled to undergo surgery that night.

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Sidebottom will be sidelined for the round 23 clash against Essendon at the MCG on Friday night, and the Magpies hope to have him back for their first final in a fortnight.

"Steele was in clear discomfort but the extent of the injury and an anticipated recovery period won't be known until after the surgery," Collingwood football manager Geoff Walsh said.

"It is certainly disappointing for Steele but the upside is that we have the break between the end of the home and away season and finals to give him added time to recover."

The injury will end Sidebottom's streak of 88 consecutive games, which started in round four, 2016.

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The 28-year-old, who has won the Pies' past two best and fairest awards, is the second AFL player in a month to suffer a ruptured testicle following North Melbourne veteran Scott Thompson's heroic effort to play on in the Kangaroos' narrow loss to Brisbane at the Gabba in round 18.

Thompson was sidelined for just one game.