BRILLIANT Port Adelaide forward Chad Wingard will miss Friday night's clash with Essendon because of a hamstring strain.

And midfielder Hamish Hartlett (hamstring) and spearhead Jay Schulz (back) will be sidelined again because of their injuries, Port coach Ken Hinkley says.

Wingard limped off late in Port's loss to Adelaide last weekend and Hinkley says scans showed a need to be cautious to prevent a more serious injury.

"We have scanned Chad yesterday because he still had some (hamstring) awareness so we're a bit mindful of that," Hinkley told reporters on Wednesday.

"With the scan there was signalling there that suggests you should be cautious - and we will be cautious.

"As much as we'd love him and need him to be out there this week, we have got to take the long-term view."

Hinkley hoped Wingard would be available next week, likewise Hartlett who missed the defeat to the Crows with hamstring soreness.

"Hartlett is probably on track to play next week, no problems," he said.

But the prognosis on key forward Schulz, who was sidelined last week by a back injury, was more uncertain.

"His will be a little more wait and see how he goes over the weekend. He will run Saturday and see where he's at," Hinkley said.

"We are dealing with a significant back issue with Jay but normally they settle down pretty quickly.

"He had some surgery in the off-season on his back and now it has flared up early so that suggests there are some issues."