The Power suffered its seventh loss of the season on Saturday night, losing by 62 points to the Sydney Swans after falling away badly in the second half.
There was further bad news following the final siren, however, when coach Matthew Primus confirmed Schulz had hurt his hamstring.
Schulz, who finished the night against the Swans with two goals from 13 touches, was playing just his third game of the year after missing between rounds two and and six due to a twisted knee against Collingwood in round one.
He made his return against Hawthorn in round seven.
"He's been out for a while so not to be able to get him through this was disappointing," Primus said after the match.
"That will be a loss for us but someone will step up."
In other injury news, Primus said Troy Chaplin finished the match with a corked calf.
But on a more positive front, the coach said he was pleased with the performance of debutant Ben Jacobs, who started the match on the bench but ended the night with 14 touches and five marks.
Primus said although his young charge made a few mistakes, they came against a team that put a lot of pressure on the ball carrier.
"I thought he showed why we wanted to play him and he is only going to get better," Primus said.
"It was pleasing he was able to find the ball."
Although it was heavy loss, Primus said the club's younger players learned a valuable lesson on what it took to succeed in the AFL.
The visitors had worked hard to trail by just six points at the long break, thanks to a determined effort against a typically hard-working Swans outfit.
"What we are going through at the moment, and whatever we go through in the next few months of the season will be the making of this group in six months, 12 months, 18 months time.
"It might not feel like it now but it will be."
Although Primus admitted the playing group was "down" at the moment, they had bounced back well on the training track following previous losses and he was confident they would do so again.
"We're in a hole no doubt about it and we've got to dig ourselves out of it," Primus said.
"If you think there's a magic formula there's not. Don't worry, they are as down as you can get after every game but they do bounce back to train and learn to get better every week."
Primus paid tribute to Sydney's midfield brigade, and the pressure it was able to exert on the match.
But the coach felt Port could have been closer or even in front at half time had it kicked better inside forward 50.
"We kicked far too many shallow which made them pretty easy for them to rebound and take it down the other end," Primus said.
