Ballo, the forward or attacking midfielder, who turned 20 earlier this month, made 13 appearances back in his homeland, including three in the Europa League. He joined our Academy in January 2018 from Viktoria Koln in Germany.
Academy goalkeeper Ethan Wady has moved on loan to Hendon.
The American, who joined the Chelsea Academy during the 2017/18 campaign, has previously gained first-team experience on loan at Tooting & Mitcham United in the Isthmian League and with National League South side Dartford. Hendon play in the Southern League Premier Division South.