MIDDLESBROUGH'S red home shirts could be replaced by red faces as the Premier League side beat Oxford United wearing the wrong kit.
The League One side gave Boro a fright coming from two goals down to draw level, however Cristhian Stauni broke Oxford hearts late on with a close range strike.
Boro's kit showed the Premier League badge on the sleeve instead of the correct FA Cup badge all clubs must wear in the competition if they are live on television.
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Boro wore the same shirts in the previous rounds beating Sheffield Wednesday and Accrington Stanley, but were under no obligation from the FA as their games were not live picks.
Teams who are featured live by any broadcaster in the UK or abroad must wear the FA Cup badge on their kit.
SunSport understands the FA will speak to Boro, but the Premier League side are unlikely to face any action.
Broadcast rights for the FA Cup were sold overseas for a reported £820million for six years from 2018, so the FA will want the correct branding shown around the world to appease broadcast partners.
Boro will now face either Manchester City or Huddersfield in the quarter final next month as they look to win their first major trophy since the League Cup in 2004.
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