Port Adelaide's depth chart is stretching to 34 with untried forward Dylan Williams adding his name to the growing list of players called to action this AFL season.

Williams, 19, will join the two teenagers called earlier by Port Adelaide in the 2019 AFL national draft - Miles Bergman (pick No. 14) and Mitch Georgiades (18) - in the 22-man line-up to play Sydney at Adelaide Oval on Saturday afternoon.

Williams, who turns 20 next week, was recruited to Alberton with pick No.23 in the 2019 national draft from the Oakleigh under-18s system in Victoria.

His elevation to the AFL line-up - as the 197th player to represent Port Adelaide in the national league since 1997 - follows a six-goal return in the SANFL against Sturt on Sunday at Alberton Oval.

Williams is the fourth player to make his AFL debut at Port Adelaide this season, following Bergman (round 1), academy graduate Lachie Jones (round 4) and fellow defender Martin Frederick (round 6) - and club debuts by Essendon recruit Orazio Fantasia and former Sydney defender Aliir Aliir in the opening round.

Port Adelaide senior coach Ken Hinkley is rewarding Williams for a solid six-week approach to his development that unfolded under the watchful eye of development coach Chad Cornes.

Williams will be part of a new-look Port Adelaide attack with the recall of key forward Todd Marshall from the concussion protocols. They will replace in the forward sector the injured pair of midfielder-forward Robbie Gray (left-knee surgery) and first-year half-back turned half-forward Lachie Jones (grade-2 hamstring strain).

"It is an opportunity created unfortunately by Robbie Gray's injury - and we have gone for a somewhat 'like for like'," Hinkley said at Alberton on Thursday afternoon.

"We know we are not replacing Robbie Gray, who is a great. But Dylan gets his opportunity off the back of some strong, solid form and with six goals (last week) it is hard to argue he does not deserve this opportunity.

"It has been a strong six weeks (by Dylan). He has been working hard and great credit to his coaches, in particular Chad who has taken him under his wing and helped him through some challenges in developing his career. The harder you work, the luckier you get - and Dylan had worked really hard for six weeks at least. He gets his chance."

Marshall's return - after missing the 50-point win against Gold Coast at the Gold Coast on Saturday - will take ruckman-forward Peter Ladhams out of the line-up to place Scott Lycett in the lead ruck role.

Port Adelaide last tried the two-ruck model of Lycett and Ladhams and the three tall forwards of Dixon, Marshall and Georgiades in the round 3 loss to West Coast in Perth.

"We think (it is best two play) Marshall with our forward stocks at the moment," said Hinkley who is denied Gray and Fantasia by knee injuries.

"We need to back in a true forward and Todd comes in and gives us some opportunities as a genuine forward.

"And Dylan has great forward craft.

"We need to kick a good score to beat Sydney.

"We are forecasting what conditions might be like (with showers on the radar). And, more importantly, it is about the talent in our front half. Todd has natural forward craft. 

"Peter, to be fair, is developing really well in that area, but we still think Scott Lycett is our first-choice ruckman and we think Todd is in front of Peter as a forward."

The third change to the 22-man line-up - to be detailed with full team selection on Thursday evening - will mark the return of experienced half-back and team leader Hamish Hartlett from the medical substitute seat.

"Hamish did really well last week, so he will play," Hinkley said. "He looked like he had some freedom back in his game and he played a pretty attacking game for us."

The "squad mentality" theme is forced by necessity to cover injuries rather than by design for Saturday night's home clash with a top-eight rival.

Of the 33 to have represented Port Adelaide in 13 matches this season, only 10 have played in every game.

"It is a great challenge for the group," Hinkley said of the tests posed by a demanding injury list. "You lose good players. Every team does at some point.

"We have dealt with that all the way through with a number of players we have lost through the season. 

"If we can get through this with the squad mentality we talked about in January, and we are giving that a real run, then credit to the boys who have been able to keep getting the wins.

"We've tested our depth a fair way. But you never know (how far injuries will stretch a squad) during an AFL season. We have found other players with four debutants. We have tested most of the players who we thought at the start of the year would be more than capable of playing AFL."

Fifth-ranked Port Adelaide (36 points, 122.9 per cent) will now host sixth-placed Sydney (32, 108.1) at Adelaide Oval at 4.05pm rather than the originally programmed 7.10pm timeslot.

"We were pretty confident it was going to be played in Adelaide," Hinkley said. "The timeslot was always up for debate. We were hopeful and confident that SA Health would allow the Sydney Swans to fly in and fly out (to Melbourne).

"We will be ready to go."

The 50-point win against Gold Coast at the Gold Coast on Saturday came with vice-captain Ollie Wines noting his midfield group needed to do better - and Sydney offers a strong test of the revision done at training at Alberton this week.

"We know what Sydney will bring and we know how hard they are around the ball with the quality of players they have around the ball," Hinkley said. "They have some hardness that is almost best in the competition. So it will be a good opportunity for our midfield group to be ready and aware of what is coming."

Port Adelaide plays its second home match in three weeks against a top-eight rival with good reason to feel confident against Sydney. Since 2017, both at Adelaide Oval and at the SCG, Port Adelaide has built a four-game winning sequence against Sydney with solid margins of 28, 23, 47 and last season 26 points.

"Sydney does the basics of the game really consistently and always have done that - and we know that," Hinkley said. "We have seen a change in their offence and everyone has acknowledged they are quite damaging from their back half - and we have some awareness of that."

A fifth consecutive win could put Port Adelaide back in the top four - dependent on the Thursday Night Football result between third-ranked Geelong (40 points, 127.7 per cent) and Brisbane (36, 128.4) - for the first time since round 8. 

Hinkley is still taking the long-term view of the premiership race.

"I'd love to beat every side every week," Hinkley said. "We have to get a number of wins together to still be playing at the end of the year and that is what we are setting out to do. 

"Unfortunately, you do lose some games in this competition. As it stands right now, the teams above us have been able to beat us and have been a bit of challenge for us. But I still believe we're capable - more than capable - of beating the top teams."