The 21-year-old Scot was brought to The Riverside by former Boro boss Gordon Strachan in May 2010.
Although he played a number of games during his first season south of the border, he made just one appearance in 2011/12, when he also spent time on loan at Walsall.
However, the left-back is getting more opportunities this season and admits it has been a long haul for him in North Yorkshire.
The former Livingston player told The Northern Gazette: "It's been a long time in coming. I have been wanting to play football and I have started to get some games.
"I am really enjoying my football right now. These things, contract situations, take a lot of time, I don't think I have anything to worry about.
"There's no rush and it's the happiest I have been since I joined and it's the most I have enjoyed my football since I started here.
"I'm enjoying Teesside. I have settled in now down here and I'm not thinking about going anywhere."