Scans have confirmed the allrounder has bone and ligament damage in his right hand after falling awkwardly while fielding off his own bowling in Monday night's loss to Hobart.

He will miss at least the final three games of the regular season, and would be in serious doubt to play in the finals that start late next week.

Sams' absence comes as a serious problem for the Thunder.

He is arguably their most important player, taking a record 30 wickets last season, a haul that earned him an Australia debut.

He has backed it up this year with another 10 wickets, while his batting has been almost as valuable with 199 runs at an average of 49.75 and strike-rate of 191.

The Thunder are one of just two clubs who do not have Australian Test players returning to their set-up to end the season.

They have also lost four of their past five games to slip from first to third, leaving them in a six-team logjam with four points separating second from fifth.

Realistically, they need to win at least two of their final three games to make the finals, with one match against the Sydney Sixers and two against Adelaide.

Australian Associated Press