Newcastle were seconds away from reaching the semi-finals on Tuesday night at Stamford Bridge, however, an error by Trippier led to Chelsea's equaliser.
Trippier failed to control a hopeful ball into the box in the second minute of stoppage time, allowing Mykhailo Mudryk to steal in and score.
But the England international's night went from bad to worse as he went on to miss his penalty in the resulting shootout.
Chelsea would win the shootout and thus progress to the last four of the tournament, giving Trippier a night to forget.
However, to make matters worse, some unrelenting Chelsea fans have discovered an old tweet of the defender's from 2014.
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"Come on Chelsea," it read, with several football emojis.
It appeared to be after the Blues faced Atletico Madrid in the Champions League, a tie they lost. Coincidentally, Trippier would go on to sign for the Spanish side in 2019.
But the tweet went viral in the aftermath of Chelsea's victory over Newcastle.
Considering Trippier's past with Burnley, Tottenham and Manchester City, his allegiance to Chelsea is unknown.
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And his error-strewn performance on Tuesday night has not been the only torrid time Trippier has had recently.
Earlier this month, the 33-year-old was at fault for two goals as Everton beat Newcastle 3-0.
Taking to Instagram, Mudryk showed some sportsmanship, albeit in x-rated fashion.
"Kieran, just wanna say to you, stay strong," he wrote on a picture of him and Trippier on his story. "Sometimes the s*** happens.
"But I think you are [a] strong footballer no matter what."