Like the first team, Dave Watson's youngsters had no game last weekend, but they will travel to face the Saints for an 11am kick-off at Staplewood Football Development & Support Centre.
Leading scorer Lewis McNall is injured but defender Lewis Gibson - who scored for England under-17s against Bosnia & Herzegovina earlier this week - has returned unscathed from international duty.
Jack Robson, Ben Kitchen and Craig Spooner are also included in the squad for the long trip to the South Coast.
United kicked off their Under-18 Premier League group three play-off campaign with a win against Sunderland before losing 2-0 to West Brom last time out.