Defender Anfernee Dijksteel and midfielder Jonny Howson have both penned new deals recently after some impressive performances this campaign.
Scroll down and flick through the pages of our picture gallery to see when every Boro player’s contract expires, according to football website Transfermarkt:
1. Duncan Watmore
Contract expires: January 2021 Photo: JPI Media
2. Marcus Bettinelli (on loan from Fulham)
Contract expires: Summer 2021 Photo: Alex Pantling
3. Patrick Roberts - on loan from Manchester City
Contract expires: Summer 2021 Photo: Alex Davidson
4. Marvin Johnson
Contract expires: Summer 2021 Photo: George Wood