Veljkovic originally joined Boro on October 16, signing for three months on a loan deal.
The 19-year-old midfielder struggled for game time at the start of his career on Teeside, but he has started to impress during frequent run-outs over the festive period. After making two substitute appearances against Millwall and Ipswich, the Serbian youth international finally made his first start for the promotion contenders on Sunday - as Boro struggled to a 0-0 draw away at Blackburn.
Speaking to Gazette Live, Veljkovic admitted that he had to work hard to be given his opportunity, but there is no doubting that his performances have been encouraging since making his debut.
The youngster said: “I had to wait two months to start a game but I have trained hard and had to wait for my opportunity.”
Despite not playing as much as expected for Karanka’s side, Veljkovic is starting to work his way into the first-team fold, and he continued to add that he is keen on extending his stay at the Riverside Stadium past the original expiration date in January - although he admitted that talks had yet to open between himself and Karanka.
“I hope I can stay longer,” he continued. “I didn’t speak with the gaffer yet but I hope we can talk soon. I thought I played well and I enjoyed it.
It is likely that, should Karanka want Veljkovic to stay, the Serb will be allowed to extend his loan with the Teeside club, with first-team opportunities likely to be limited at White Hart Lane. Karanka has already proven that he is willing to utilise loan stars for the good of his side - with Spurs teammate Ryan Fredericks, as well as Chelsea forward Patrick Bamford, turning out regularly - and, having started to impress, Veljkovic could well be given an extended run in the first-team come the start of 2015.