The 19-year-old returns to Austria, the country where he spent much of his childhood and for whom he represents at Under-21 international level.
After arriving at Chelsea from Viktoria Koln in Germany three-and-a-half years ago, Ballo has impressed for our Under-18s and development squad, hitting double figures in his first full season at the club while playing in an attacking midfield role and finishing as the youth team’s top goalscorer.
A versatile offensive player, the teenager has played in a variety of positions in attack for Andy Myers’ Under-23s, helping the team to the Premier League 2 title in 2019/20 and, more recently, operating as a striker. A strong second half of last season saw the Ivory Coast-born forward end the term as our joint-top goalscorer at that level.
Rapid Vienna are currently fourth in the Austrian Bundesliga after the opening six matches. They have been drawn in a Europa League group alongside West Ham, Genk and Dinamo Zagreb.