PORT Adelaide chairman David Koch should not have expressed his grievances via social media and should have addressed it in-house instead, Power premiership player Kane Cornes says.

Koch, 60, slammed his team following its heavy 86-point loss to GWS last Sunday, responding to a fan on Twitter to brand the performance "a disgrace".

Port a disgrace, chairman Kochie declares

He added that such performance undermined "a historic week" in which the club signed a memorandum of understanding to play an AFL match in China for premiership points.

The Port president defended his remarks on Saturday night and said the playing group should "harden up" if they were offended by his social media outburst.

Cornes, 33, said Koch made an error of judgment by posting his tweets last week, but made another mistake by not backtracking on his comments in a pre-game interview on Channel Seven.

"He shouldn't be responding to a fan on Twitter on a Sunday night after that performance … he should be doing that in the right way," Cornes, a four-time Power best and fairest winner, told Crocmedia on Sunday.

"If he has that opinion, he needs to tell the players that first – face-to-face in a meeting.

"But then last night, I would've loved for him to come out and have said, 'Look, it was (in) the heat of the moment, we'd had a big week, we'd announced China, and then the players performed like that, I was frustrated, I sent the tweet out (and) it was the wrong place to do it.

"But he didn't, he stood by his comments, and then to go even further and tell the players to harden up, it's not what the club needs."

On Saturday night, Koch acknowledged his tweets had "unsettled" some of the Power's playing group, but did not back away from his strong stance.

"As I said to 'Trav' (captain Travis Boak), the playing group during the week and the coaching group, 'Hey, I praise you guys constantly, I'm your biggest supporter, but everyone in this organisation is accountable'," Koch told Channel Seven prior to Port's clash against Geelong at Adelaide Oval. 

"He was saying it unsettled some players and my message is, 'Harden up'."

The Power were left reeling after their 48-point loss to the Cats, which leaves them with just two wins from the opening five rounds.