Will Gidman will act as player-coach for the Second XI while Min Patel is away with the England Under-19 squad.
The 33-year-old is a ECB Level 3 coach and is working towards his Level 4 qualification and a career in coaching.
The former Durham, Gloucestershire and Nottinghamshire all-rounder will retire from playing at the end of the 2018 season and is relishing the opportunity.
Gidman, who has scored almost 5,000 runs and taken 276 wickets across all formats, said: “I feel I’ve given the game everything I can as a player and the time is right to move into coaching.
“I’ve enjoyed working with Matt Walker, Allan Donald and the first team squad in recent weeks and with Min in second team cricket too.
“The chance to lead the second XI for a couple of weeks and work with some exciting young talents is a great one for me as I make the transition from cricketer to coach.
“I’ve worked with some experienced players and coaches and hope to share my knowledge with the lads and help them on the pathway to becoming established first class cricketers.”