The Power talent kicked two goals in Sunday's 14-point loss to the Suns but gave away four free kicks and had just nine touches despite attending 10 centre bounces.
He hadn't registered a disposal when he gave away a 50 metre penalty after shoving Suns midfielder Sam Flanders, who he had just tackled high, to the ground in the second quarter.
Horne-Francis was then caught up in another scuffle with Nick Holman in the final, flinging the Suns hardman to the turf.
Six third-quarter possessions swelled his numbers, after just two touches to half time and one in the final term.
Port coach Ken Hinkley didn't excuse his youth when addressing the former No.1 pick's tough day.
"He's got to be better than he was today in some moments ... and we won't accept that that's okay," he said.
"He's learnt alot but he's still got a lot more to learn.
"He's an aggressive player who seeks out body contact and once you let the oppo (opposition) get a look at it, they tend to come after you a little bit more.
"Jason's learning to deal with that and he has to get better."
The loss cost Port, who had won two-straight, fourth place in the midst of a 12-team battle between second and 13th separated by just two wins.
A concussion to Lachie Jones and bizarre hip injury to forward Todd Marshall compounded Port's problems.
Jones was taken high by Alex Davies while Marshall's legs took the weight of falling teammate Charlie Dixon, the forward to have scans to determine the extent of the damage.
"I've been around a long time, seen a lot of strange things happen on the footy field and that's another one to add to the collection," Hinkley said of the nature of Marshall's injury.
"Ultimately we paid a big price."
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