Captain Travis Boak calls on Port Adelaide players to lift pressure early in matches Travis Boak chases Richmond's Nick Vlastuin. CAPTAIN Travis Boak says Port Adelaide needs to improve its defensive game if it is to rebound from consecutive defeats. After winning its first five matches, the Power has slumped to disappointing losses to North Melbourne and Richmond and Boak has called on his team to get back to the pressure game which served it so well during its record start to the season. "It is disappointing that after a great start to the year our defensive stuff has probably dropped off a bit," he said. That's what really held us in good stead in the first five weeks but it's dropped off and will be a big focus for us this week. I'm sure if we do that and improve we can get back on track. Port has stumbled out of the blocks in the past two weeks, falling 38 points behind the Kangaroos and 37 in the first quarter against Richmond. Damningly, the Tigers had 43 of the first 53 disposals at AAMI Stadium on Saturday, leaving the Power playing catch-up all day. Boak put the disastrous start down to a lack of pressure from Port. "It's not the whole first quarter, it's just that patch of five or 10 minutes where we have a lapse of concentration," he said. We have been giving up too many contested marks and letting teams work their way down the ground and score too easily. We have to fix that, get that defensive aspect to our game back and be a team which is really hard to score against. We just need to be harder to play against, be harder to score against. Boak said the Port players were "angry and frustrated" at losing two games they thought they were good enought to win. "And now the challenge is to bounce back, which we are looking forward to," he said. Boak said he hopes former captain Dom Cassisi (hamstring) and half-back Jasper Pittard (hip flexor) will prove their fitness on the track during the week and be available for Sunday's clash against Carlton at Etihad Stadium.