Simmons and Nwachuku loaned outJack Simmons and Nnamdi Nwachuku, both regulars in the U's development squad, will be with the Ryman League Premier side for the next few weeks.
Two U's youngsters have gone out on loan to Leiston.
They will be playing for a familiar manager though, with Academy coach, and former U's midfielder, Steve Ball in charge at Victory Road.
Leiston sit in nineteenth place and will be hoping the attacking prowess of both the youngsters will lift them away from the bottom end of the table.
Both are expected to be in the squad for this Saturday's game, away at Thamesmead Town, who are two places below Leiston.