Middlesbrough face one of their toughest tests of the season on Saturday when they travel to Sunderland. Regis Le Bris played down the rivalry between Middlesbrough and Sunderland in his pre-match press conference on Thursday afternoon. However, despite some Sunderland fans not classing the fixture as a derby, it is sure to be a feisty affair for a number of reasons. The Tees-Wear derby is the oldest competitive football derby fixture in the North East, beginning on November 26th, 1887. This season’s fixture is once again set to be a massive affair, with both teams having promotion aspirations…