Patrick Kisnorbo and Saul Deeney have been given the opportunity to try and earn contracts with Derby.
Versatile Australian defender Kisnorbo was released by Leicester earlier this summer following the expiration of his contract.
The 28-year-old, who also spent time with Hearts earlier in his career, has now linked up with the Rams for a trial period.
Goalkeeper Deeney is also training with Derby in an attempt to earn a permanent deal.
Deeney played for Nigel Clough at Burton but is now a free agent and will be hoping to impress.
Both players featured in the pre-season friendly victory over Burton on Saturday, along with fellow trialist Mark Fotheringham.