Fremantle coach Justin Longmuir has conceded his team faces a mental battle in the wet after back-to-back losses in slippery conditions dealt his team a dramatic "reality check". 

The Dockers slid to fourth on Sunday night after Collingwood dealt them a lesson in wet-weather footy at Optus Stadium, adjusting to the conditions throughout a heavily contested game to win by 36 points.

Longmuir said his team, which also lost to Gold Coast in the wet last Sunday, did not need to change its gameplan, which has proved successful this season in dry conditions. 

The players did need to rediscover trust in their wet weather ability, however, with the issue set to be a hurdle for the team until they do. 

"I think it is a mental thing. Players read too much into the conditions and it affects their games too much, especially with ball in hand," Longmuir said on Sunday night. 

"Whether it's the actual conditions or we think it's wetter than it is or drier than it is, I think that second quarter we just fuelled their forward game and fuelled their field position.

"We turned the ball over in really poor areas going for stuff that in the conditions wasn't on, and then as it dried up we kept playing wet weather footy when they were playing dry weather footy.
"We just got caught in-between with our ball movement and clearly we couldn't score or keep the ball in our front half after the first quarter."

Longmuir said the Dockers' poor fortnight in slippery conditions had a lot to do with their ball-handling and mindset, with the team beaten in the pressure stakes by the Magpies' convincingly and fumbling too often. 

He said the issue would need to be addressed both on the training track and with education, but training for wet weather games in Perth was difficult. 

Losing two games in a row for the first time this season had provided a reality check for the club. 

"We were riding high, and everyone was getting way ahead of themselves," Longmuir said. 

"If you get marginally ahead of yourself in footy, it gives you a reality check, and we’ve gotten that. If you’re off in any part, you get what you deserve. So it’s a reality check for us."

Gallery: Peel v South Fremantle

In contrast to the Dockers' shortcomings in the wet, Collingwood coach Craig McRae said the heavy pre-match rain had encouraged his team.

The club's most impressive win of the season had left the first-year coach proud after the team went searching for its DNA during the week following a disappointing 48-point loss to the Western Bulldogs.  

"We were smiling when it started raining, we like to play in the wet and we had an opportunity to display that," McRae said.  

"We were disappointed with our efforts last week and we came here with a purpose. 

"I am really proud of the boys. Last week we were disappointing and today we're proud."

McRae said young forward Ollie Henry's terrific performance was a lesson in resilience after booting 0.3 against the Bulldogs and placing his position in the team in jeopardy.  

The 19-year-old sunk the Dockers with four second half goals after coming into the game as a replacement for tall Mason Cox, who suffered a finger injury. 

"His position in the team was up for grabs. We spoke about it for half an hour at match committee," McRae said of Henry. 

"I spoke to him and said you have to be more present and make the most of the opportunities you have … today he looked like a player who had more composure." 

Young forward Jack Ginnivan was again important for the Magpies, kicking 2.2, with his pre-emptive goal celebration in the fourth quarter bringing a smile to McRae's face when he was asked about it.  

"What do you do there? You want them to be themselves," the coach said.  

"Kick the goal and then celebrate with your teammates, might be the message. But he's been very good for us."

Justin Longmuir post-match Q&A
Young: Intent not enough
Match report: Pies down Freo in the wet