The Bluebirds booked their place at Wembley with a penalty shoot-out win over 10-man Crystal Palace, with Heaton pulling off two impressive saves during the shoot-out.
This got us thinking about how many ex-Reds have appeared at the new Wembley in a domestic cup match since the stadium was opened in time for the 2007 FA Cup final.
Having looked at the line-ups for the four League Cup finals and thirteen FA Cup semi-finals and finals, we've come up with the names of NINE ex-United players. Can you work out who they are?
Once you've had a good think and compiled your nine names, check our answers page.