WEST Coast midfielder Chris Masten could miss the first month of the premiership season after suffering an left ankle sprain in the Eagles' intra-club match on Saturday. 

Masten suffered a high left ankle sprain and will have his ankle in a moon boot over the next couple of weeks before starting a rehab program.

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The Eagles' round three clash with Fremantle on April 9 would just one day shy of eight weeks from the initial injury, but the club is unlikely to take any risks with one of its most important midfielders.

Masten, 26, had had an uninterrupted summer after carrying a hamstring problem through last year's finals series. He suffered the injury in round 23 after missing the previous two games because of a controversial biting suspension incurred after the second Western Derby.

He was subbed out of the preliminary final against North Melbourne but gathered 20 disposals in the Grand Final. 

The Eagles' midfield is already at less than full strength with both Jack Redden (adductor) and Dom Sheed (knee) working their way back from injury.