"He's one of those nippy players who can be used on the flanks. It'll be interesting to see how quickly he adapts to the speed of the German game."
Stuttgart, who won the 2007 Bundesliga title, are currently mid-table in the league with two matches remaining.
Rojas said in a statement he is delighted with the move and looks forward to the challenge of stepping up to European football.
"Dad and I spoke to the responsible parties at VFB and they gave us the impression that they really wanted me here. It's great for a player when a club shows just how much they want you. It'll certainly be a big challenge."
Rojas played for Waikato FC in the New Zealand Football Championship before signing with the Wellington Phoenix in 2009. In 2011 Rojas, joined the Melbourne Victory on a two-year contract and finished the 2012/13 season as the top player in the A-League.
Rojas will join former A-League players Mitch Langerak, Robbie Kruse and Nikita Rukavytsya in Germany's top flight.
- Newstalk ZB/nzherald.co.nz