Pompey’s quest to end their winless run will meet the toughest challenge possible this weekend.
Fratton Park will be visited by a Sunderland side who are currently sitting at the League One summit and enjoying a rich vein of form.
The hosts, meanwhile, received plenty of criticism following a poor display in Tuesday evening’s defeat at Burton.
Cowley accepts that was warranted, but has now switched his focus on trying to deal with the Black Cats.
The Blues boss said: “It’s probably best game we could have and provides us with an opportunity to put the wrongs of Tuesday right.
“The two performances before that – against Plymouth and Charlton – were positive on the whole, but we couldn’t turn them into wins.
“When you don’t do that and then play poorly and lose, as we did at Burton, you’re rightly going to get criticised.
“There’s nothing we can do about that and just have to accept it. What we can do, however, is affect what happens next.
“Whether we win, lose or draw, we always try to learn from it. When you lose you want to find out why and make sure it doesn’t happen again.
"There’s a decision to make on Saturday because there’s a potential opportunity for some boys who have been on the outside."
“We always have to be demanding of the players’ performance. I’m the first to tell them when they’ve done well and it’s the same when they come up short.
“There’s a decision to make on Saturday because there’s a potential opportunity for some boys who have been on the outside.”
Sunderland thrashed Cheltenham 5-0 in midweek and have not suffered a defeat since also being beaten at Burton in mid-August.
Cowley said: “They’ve recruited well and there’s real competition for places across their group, with a high quality of attacking players.
“I really like their movement at the top end of the pitch and they carry a real goal threat, while also being hard-working against the ball.
“After nine games they are the best team in our division and we have to respect that, but certainly not fear it.
“We’re a team with good players and have to put a game-plan together that allows us to get on the right side of the result.”
Miguel Azeez was absent for the Pirelli Stadium trip with a groin problem and Cowley is not sure whether the Arsenal loanee will be fit to face Sunderland.
He said: “Miguel trained with us on Thursday, but the game on Saturday might come too soon for him. We’ll have to wait and see.”