The south-coast club have just two points on the board from their opening seven Championship games and sit bottom of the table.
It is a start almost as wretched as the one they made to their 2009-10 Premier League campaign, when they lost their opening seven matches as they were relegated amid serious financial difficulties which forced the club into administration.
Pompey host a Leicester side on Friday night who have fared only marginally better in the league, with just one win and two draws from their first seven league matches, but the Foxes will be boosted by a 2-1 win over Steve Cotterill's men on Tuesday in the Carling Cup.
That was a third defeat in a row for Pompey, and South African skipper Mokoena has rallied his team to turn their performances and quality into points.
He told the club's official website: "It's been a similar start to last season. We're playing well but we just can't seem to get that first win.
"We want it to come as soon as possible because it's not nice being bottom of the table.
"Luck hasn't really been going our way so far this season but we have to stop conceding soft goals.
"With the players we have in our squad we're confident things will change soon and hopefully we can beat Leicester to lift everyone's spirits.
"But it's time to stop talking about what we can do and show it on the pitch."
Richard Hughes will serve a two-match ban, starting against Leicester on Friday, after being sent off on Tuesday.
The Foxes have been boosted by the news that striker Lloyd Dyer has signed a new contract which keeps him at the Walkers Stadium until 2014, after making a bright start to the current campaign.
City boss Paulo Sousa told his club's official website: "I am very pleased that Lloyd has agreed to sign this contract extension.
"He has been playing well and is the calibre of player that we hope to have at the club."