During the 2005/06 season, the Shrimpers edged Colchester United to the League One title, being skippered by current Blues boss Kevin Maher.
READ MORE: All the team news ahead of Blues' tie with Southport
For the U’s, Southport chief Neil Danns was a key figure in the centre of the park.
And Saturday’s clash will therefore bring back some great memories for both bosses.
“It was a really special time for both clubs who are obviously local rivals,” recalled Danns.
“We both ended up getting promoted and it was two really good teams.
“There was a real feel-good factor around both locations and Southend were a really good side then with the likes of Freddy Eastwood and Kevin.
“They’re really fond memories from that time and I actually got to visit there back in 2019 when I played in a charity game between those two teams which was great.
“It was a great occasion and we’ll both have great memories of that time. It will be nice to see Kev again and to shake his hand.”
The winners of this weekend’s tie will create more special memories by heading to Wembley for the FA Trophy in mid-May to face either Wealdstone or Marine.
Southport, who are 14th in National League North, have beaten National League duo Eastleigh and Yeovil Town to reach the final four.
But Danns knows his team will not be favourites to win against Blues.
“This is a really tough challenge for us,” said Danns.
“We know they’re flying high in the National League and they’ve got a really, really good side.
“It’s been hard not to keep an eye on their results since the draw and Kev is doing a brilliant job there, so we’re fully expecting a really, really tough game.
“We know we’re underdogs but that’s the beauty of cup football.
“We’re really optimistic like we have been in every round, but I’m sure Kev will be the same. It will be a great day and the team who wins has an absolutely amazing prize at the end of it.”
Southport head into the game having triumphed in six of their last seven games.
And Danns is excited to be facing the Shrimpers.
“I’m really looking forward to it,” said the 43-year-old.
“It’s a really big achievement for the club to have got this far in the FA Trophy this season and it’s been a long time since the club went this far in the competition.
“It’s one that everyone involved with the club is looking forward to. We’ve got a big crowd coming and it’s going to be good.”
But Danns will not entertain any talk of reaching Wembley.
“There’s no point looking any further ahead than what’s in front of you,” said Danns.
“We’ve done the same in every round and we’ll do it again on Saturday.”