Premiership Captain Tony Shaw has put American Mason Cox on notice, saying he needs to "come down to earth."

Shaw believes that the tall forward has had "too much publicity" after his breakout 2018 season that almost took the Pies to premiership glory.

“Big Mason Cox, he’s had a horrible run,” Shaw said on Macquarie Sports Radio.

“He had a ripper year last year, but just hasn’t had the same this year.

“He had an injury, but every time you open the papers, there he is, he’s doing this and he’s doing that, I just think ‘come on mate, just come back a bit and come down to earth’.”

Cox has been scrutinised for his output so far this season and especially against the Hawks last Friday night.

He has played 10 games this season, booting 15 goals and having nowhere near as much impact as he did last season.

Coach Nathan Buckley still backs his big man, but admits he needs to do better against the Eagles if Collingwood stand a chance.

“He’s not going to mark everything but we do need him to compete really heavily as we do with all our forwards or our key backs,” Buckley said.

“Our aerial work wasn’t great last week in the front half against Hawthorn and it needs to be. It needs to be better this week if we’re to give ourselves a chance.”

The Pies have been poor since coming off the bye, having just scraped through for a win against the Bulldogs but were at the hands of a thrashing against North Melbourne and the most recent loss against the Hawks.

Shaw, along with the black and white army, are worried that this stretch of bad form is becoming a trend heading into the pointy end of the season, and must be changed before September.

“I don’t know what’s happened, it looks like it’s a trend… There’s been no flow, their inside 50 count … Collingwood’s only averaged in the last month about 30-odd, you’ve got to have 50-60. If you’re not getting it in there, you’re not scoring,” he said.

“Hopefully it’s only about doing it now and having that lull — it’s better having it at this time … than having it during a finals series when you don’t look like winning a game.”

The Pies have a tough stretch as they play West Coast, GWS and Richmond in the next three weeks.