Carnell has been an assistant with the Red Bulls since March of 2017. He was previously an assistant for the Orlando Pirates in South Africa's Premier League.
As a player, Carnell made 229 appearances in all competitions as a defender in the Bundesliga and 2. Bundesliga in Germany between 1998 and 2010. He was also a starter for South Africa's 2002 World Cup squad.
Carnell's first match as interim head coach will be on Sunday against the Philadelphia Union at Red Bull Arena (7 pm ET | MLS LIVE on ESPN+ in the US and DAZN in Canada).