Wicketkeeper Gareth Cross has left Derbyshire after being told his deal will not be extended for next season.
The 30-year-old joined in May as injury cover for Tom Poynton who was ruled out for the season after a road accident in which his father Keith died.
Academy product Harvey Hosein will play in the final two Championship games.
Elite performance director Graeme Welch said: "Gareth stepped in at a difficult time. He's fitted in really well and we wish him all the very best."
Hosein, 18, will make his debut in the match against Surrey, which starts on Monday.
Welch added: "We must now look towards the future and this is a perfect opportunity to give Harvey, who is showing real potential, a chance.
"With Tom Poynton's rehab also progressing well, we have some promising options."