Derbyshire all-rounder Matt Critchley has signed a new four-year contract, keeping him at the club until the end of the 2020 season.
The leg spinner, 20, has taken 21 wickets this season and scored 319 runs in all competitions.
Meanwhile, Callum Parkinson, 19, will join Leicestershire at the end of the season after turning down a new deal.
He has played four times for Derbyshire after making his first-class debut against the Foxes in August.
Critchley said of his new contract: "The club has big ambitions and I'm looking forward to playing my part.
"We have a lot of young talent who are all hungry for success and I'm confident we can achieve it here at Derbyshire."
Critchley will link up with Australia legend Shane Warne at Lord's next week as part of a specialist spin coaching programme.