Chelsea defender Kalas: Villas-Boas happy for me to make Vitesse Arnhem loan move
The Czech Republic prospect was outstanding on the 5-0 defeat of Roda JC on the weekend.
"There are so many good players at Chelsea," Kalas told Voetbal International.
"Of course it's great if at a young age you're at a top club, but you need to continue to play. That's why coach Andre Villas-Boas was pleased that I was going to Vitesse."