Sports were defeated 2-0 in the Hinchingbrooke Cup first round by Northern Star earlier in the season, leaving Plummer to label his Sports side as "massive underdogs" for their Vase clash on Friday.
Peterborough Sports v Peterborough Northern Star
The FA Vase
Second Round Proper
7.45pm, Friday 21 November 2014
Peterborough Sports & Leisure Club
Winners receive £1200 from prize fund
"I think this game will be slightly different to the last one as we're definitely massive underdogs for the game," admitted Plummer.
"They're the higher division side and they've already beaten us this year, but we'll be going out to give it our best shot that's for sure.
"It's a game to savour for all of us. There should be a big crowd, a great atmosphere and, I would hope, a cracking game."
Both teams have made strong starts to their respective United Counties League campaigns. Peterborough Sports sit atop of division one, while rivals Northern Star are fifth in the league above.
And when asked about his time at his former club, Plummer added: "I'm very familiar with their set-up, I've played and managed for them and we had a fantastic FA Vase run in the 2011-12 season when we got to the quarter finals.
"My assistant manager has also played for them and four of the team that were in that FA Vase run are now part of my team at Peterborough Sports, including the captain Ali Nyang."
However Sports will be without Nyang and Scott Bogusz after they both received straight red cards in the previous round, a heated affair with Welwyn Garden City.
They may also be without first-team goalkeeper Luke McShane through injury.
Northern Star had a more routine route to the Second Round with a 1-0 victory over Stotfold, where former Sports player Jordan Macleod played a big part in their only goal.
This game has been brought forward to Friday evening to avoid a clash with Peterborough United, who play at home on the Saturday, to try and encourage more fans to attend the game and maximise revenue for both clubs who will share the gate receipts.
