Devon's director of cricket Keith Donohue admits his side are "crying out for experience" ahead of their three-day Minor Counties game at Berkshire.
They are second bottom in the Western Division and were most recently beaten inside two days by Herefordshire.
Liam Lewis will open the batting at Finchampstead in his first appearance in the competition this season.
"It's become pretty clear we're crying out for some experience in the batting, and Liam has that," Donohue said.
"Liam probably would have played before now had he been available.
"We have known from the start this season was about bringing in our youngsters and that won't change."
A teacher-training course means that Lewis has only been able to play one-day cricket this season until now.
Ben Green will also return on Sunday while Harvey Sargent and Ben Williams, who made their debuts in the Herefordshire defeat, have been left out.
Pace bowler Jack Popham, who is on a dual-registration deal with Gloucestershire, is likely to miss the rest of the season due to a stress fracture in his foot.
"I don't expect to see Jack again this season - and I doubt anyone will until next year," added Donohue.
Devon squad to face Berkshire:
L J Lewis (Sidmouth), B G Huxtable, M H Curtis (both North Devon), M W Thompson (Torquay), M C Golding (Bovey), B G F Green (Exeter), J H J Mailling (Plympton), Z G G Bess (Exeter), T S Anning (Exmouth), D G Bess (Exeter), R A Stevenson (Torquay), C L Miles (Sidmouth).