ANOTHER top NAB AFL Draft prospect has suffered a serious injury setback, with Western Australia's gun midfielder Deven Robertson requiring a shoulder reconstruction.

Following the season-ending surgeries to likely first-round picks Brodie Kemp (knee) and Josh Worrell (shoulder), Robertson, who is also set to be a top-20 selection, has had his season cut short by injury.

The midfielder starred at the under-18 championships, captaining his state to the division one title on the way to winning the Larke Medal as the best player in the carnival, but suffered the injury in the final round win over Vic Country.

Robertson won the Larke Medal as part of WA's U18 division one-winning side. Picture: AFL Photos

"He dislocated his shoulder in the last game of the championship in the second quarter but played out the game, which is testament to his resilience and mental toughness," WA state talent manager Adam Jones said.

"He's now booked in for surgery next week, so he'll have that repaired and be out for the rest of the year."

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Robertson was also named captain of the under-18 All Australian team after his standout series, where he averaged 30 disposals, seven tackles and five clearances and won his side's most valuable player award.

The 18-year-old, who is the nephew of former West Coast skipper and current Hawthorn assistant coach Darren Glass, is viewed by some clubs as among the best handful of midfielders available in the draft.

However, the late-season surgery means he is likely to start his first AFL pre-season not completing all training. It is expected to rule him out of testing at October's NAB AFL Draft Combine.

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Although the injury prematurely ends Robertson's season, his campaign has been a successful one after a lift in his fitness standards over summer.

"His improvement from last year to this year was massive, and part of that was a big wake-up call with how he presented in December and some frank words with our coach Peter Sumich," Jones said.

"From the Christmas break onwards, you just saw a fiercely-determined man who did everything in his power to get himself in tip-top shape in the championships and his leadership grew to another level. He basically carried the side on his shoulders with how he went about it."