Kenny Jackett insists that only hard work will help Pompey recover from their recent League One slump.
A chastening defeat at Northampton on Saturday means they have won just three of the past 11 games.
And things do not get any easier, with an in-form Sunderland side visiting Fratton Park for a televised contest on Tuesday evening.
But Jackett believes his squad are capable of revitalising their promotion bid by securing a positive result.
The Blues boss said: “We’ve got to be better than we have been and it’s an excellent chance to bounce back live on the television against Sunderland.
“There wasn’t any intensity to our defending on Saturday and at times we either didn’t value it or couldn’t execute it well enough.
“We were out of the game after 40 minutes and that’s what was so disappointing – and it’s not like us.
"The next game is always the most important one, so we’ve got to learn and not give cheap goals away."
“The players looked slightly shell-shocked, but I’ve definitely got confidence that they can return to winning ways.
“We have to pick up some momentum and the next game is always the most important one, so we’ve got to learn and not give cheap goals away.
“But we also need to have the attitude that we can have a go at Sunderland. Nothing beats hard work. Nothing beats competing. Nothing beats defending as a team.
“We’ve got to make sure we put pressure on the opposition. They are a good side – they always have been and they always will be.
“However, it’s our own performance that we need to take responsibility for. We have to get that right.”
Jackett will have more options to choose from against a Black Cats outfit who sit fourth in the standings.
He said: “James Bolton came through his second half appearance at the weekend, while Michael Jacobs and Haji Mnoga are both available again and good options to have.
“In a lot of our positive performances, Michael has given us balance on the left, so it’s nice to have him back.”
Please note that as Tuesday’s game is being shown live on Sky Sports, it will not be streamed via iFollow. Audio commentary will be available as normal.