The Netherlands international tore his anterior cruciate ligament in a defeat at Napoli last month, ruling him out of the remainder of Roma's season as well as his country's FIFA World Cup campaign in Brazil.
Despite the setback, the 24-year-old is focusing solely on returning to action better than ever.
The former PSV midfielder told the club's television station: "There are worse things in life.
"Now I am concentrating on my recovery and I'm thinking about the players who have returned stronger and more mature after an injury of this type.
"That will also be the case with me. I feel a bit better and I'm working every day to come back. I'm only thinking about getting back on the pitch.
"The team is very strong and I can't wait to get back and play in the Champions League.
"The support coming my way is fantastic and gives me strength, I am touched by all the support I have received.
"It's my first serious injury. It makes you realise how much you stand to lose but there are worse things in life than this."
