Vuckic was hurt at Villa Park on Monday night in the reserves' 2-1 win over Aston Villa.
Pardew said: "It was an emotional night. Haris knew straight away it was a serious injury. He's had so many injuries that I think it was one too far for his own mind.
"We were upset for him and we will wait for news on the scan.
"If our fans want to send him any messages it would great, because he is hurt by what was happened."