Charlie Wyke says Sunderland must repay disappointed fans by starting their play-off campaign with a win.
The Black Cats finished the regular season with disappointing defeats away to Fleetwood Town and Southend United.
Sunderland had sold out their allocation at Roots Hall and will be backed by a big crowd when Portsmouth arrive for the first leg of the semi final on Saturday night.
Wyke says a win is the best apology for a hugely frustrating week.
“We are really disappointed,” Wyke said.
“We’ve got to dust ourselves down and look ahead to the game Saturday. We know what we’ve got to do now, we’ve got to win three games and that’s all we can focus on.
“It’s hasn’t quite happened for us this week.
“We’ve been really disappointed with the results and the performances, we’ve got to address it.
“All we can do is apologise [to the fans],” he added.
“And the only way we can apologise is by going on Saturday and winning, and look forward from there.
“The fans have been fantastic all season and I’m sure they’ll come out in force. and support us.
“Everyone will be disappointed after today, for us we’ve got to look back on what we did wrong, where we can be better and address it.
“We’ve got to keep that mood upbeat, train hard and look forward to Saturday.”
Drawing Portsmouth means that the two sides will face each other five times before the campaign is out.
The Black Cats are yet to beat Kenny Jackett’s side but were by far the better team when they met at the Stadium of Light last week.
Wyke says being clinical will be key.
“We know what they’re about,” he said.
“We’ll do our analysis and see where we can hurt them, we’ve played them a few times this season and haven’t beaten them but I think it’s time to put that right now and get a bit of revenge.
“We didn’t put our chances away on the day [last time they played] but we know we can create them and we’ve just got to take then when they come [this time].”