At 12 noon UK time this Monday, February 15th, there will be a draw at UEFA's HQ in Nyon.
At this stage of the competition no teams are seeded and teams from the same country can play each other.
There were two routes to get to the last 16. One was to qualify from a Champions League group. The other, like Boro, was to work your way through as domestic champions, the champions of your country.
The winners and runners-up of the same group in the UEFA Champions League path cannot be drawn against each other.
Neither can the winners from the UEFA Champions League path be drawn against each other.
The 16 teams are divided into two pots of eight. One pot comprises the winners from the UEFA Champions League path and the other from Boro's route, the domestic champions and knockout path.
Round of 16 matches are played on a single-leg basis played over 90 minutes with penalties if needed. There is no extra time.
So what are the possibilities?
Boro can only draw one of the following:
Barcelona, Benfica, Chelsea, Dinamo Zagreb, Lyon, Manchester City, PSG and PSV Eindhoven.
The game must played between Tuesday February 23 and Friday February 26.
Home or away?
Whichever team comes out of the pot first is the home side.
The first tie drawn will see a Champions League side at home.
The second tie drawn will see a domestic champions path side at home.
And so it continues alternately through the eight ties.