Now Sunderland are semi-final foes – yet, crucially, a Fratton Park second leg remains in the diary.
Certainly, Christian Burgess is convinced of the significance hosting Jack Ross’ side on Thursday, May 16.
The central defender is among a handful of survivors from 2015-16, when Plymouth inflicted heart-breaking League Two semi-final elimination at Home Park.
Paul Cook’s side ventured to Devon’s south coast in May 2016, clutching a 2-2 draw from the first leg.
Peter Hartley’s last-gasp winner settled matters in favour of Derek Adams’ side, forging an aggregate 3-2 triumph.
This time around, though, Fratton Park will stage that decisive second leg – and the visit of Sunderland.
Burgess said: ‘Back then I remember saying that having the second leg at home wasn’t important, that it didn’t matter, but statistics will prove that wrong.
‘From what I have seen, generally the team at home second seems to do better.
‘It’s not a forgone conclusion by the way, there are some years when it doesn’t happen, but over a period of time it has that trend.
‘The year we lost at Plymouth in the second leg had its anomalies. We had a goalkeeping crisis, an injury crisis, all those factors didn’t help us, so I’m not sure about that second leg. You can never say how much it played a part.
‘I also think we did fairly well considering, it’s not like we got pumped and were never in the game.
‘Alternatively, the atmosphere at Fratton Park was unbelievable, you remember that noise when Sparky (Marc McNulty) scored an early goal. Imagine if that was the second leg?
‘I’m sure it will be a massive atmosphere at home in the play-offs.’
Pompey’s first leg kicks off on Saturday (7.30pm) at the Stadium of Light.
That represents the Blues’ first play-off involvement since that fateful May 2016 day, when current crop Burgess, Matt Clarke, Gareth Evans and Ben Close were all involved.
The 27-year-old added: ‘Plymouth was a low point, so many things conspired against us in the end.
‘You felt we couldn’t have done a lot more, we were running out of steam. There were problems all over, people even carrying injuries on the bench.
‘This time around, I feel the second leg at Fratton Park will be amazing, while Wembley is a toss of the coin, a huge opportunity and anything can happen on the day.
‘We just want to make sure we go up.’