Warringah coach Darren Colman believes his side learnt some important lessons from the two northern beaches derbies played already this year.

In round 10, Warringah beat Manly 17-16 at Manly Oval before the Marlins returned the favour in round 16, beating Warringah 35-26 at Rat Park.

Ahead of Saturday’s do or die preliminary final, Coleman admitted physicality has been the common denominator in both matches.

“In the game we won at Manly, we didn’t play great. It was a greasy day and we didn’t attack well but we played tough and won on the back of our defence. In the return game at Rat Park, they were definitely more physical and that’s something we’ve spoken about this week,” Coleman said.

“When Manly have played well this year, it’s been on the back of their physicality. When they do that, their forwards get a roll-on and their centres provide a lot of punch, so we need to match them there if we want to be in the game.”

While Manly outscored Warringah by more than 100 points during the regular season, the Rats finished the year with the competition’s best defensive record.

“At the end of the day aggression is the key and if you can stop them getting over the advantage line, you can reset your line and go at them again. If they punch through, you’re on the back foot and forever chasing your tail,” Coleman added.

After finishing third and beating Randwick 49-13 in the opening week of the playoffs, Warringah will host Saturday’s preliminary final at Rat Park following Manly’s shock loss to sixth placed Eastwood last weekend.

The minor premiers dropped just one match in the opening 13 weeks of the 2017 season, but have won just two of their last six matches.

In the past three weeks, Manly have leaked on average more than 45 points a game.

“I didn’t take too much from the Penrith game but I thought last week they were a little unlucky,” Coleman said.

“They had two intercept tries and a fairly dubious penalty try in the first few minutes. If you take three tries off Eastwood, then suddenly it’s a different game.

“The Wests game was interesting though. They were able to get quick ruck ball and were able to play flat and in their face and Manly leaked points consequently, as most sides would.

“Wests probably played similar to how we would like to play with an up tempo style and Eastwood showed us a few other ways to score points against them as well.”

Flyhalf Hamish Angus is in a race against the clock to recover from a hamstring injury, but Coleman said his captain would be given until kick off to prove his fitness.

Alternatively, Angus could play from the bench on Saturday, leaving 34-year old former London Irish playmaker Myles Dorrian to start again in the No.10 jersey.

“As much as we miss Hamish, Myles is the perfect replacement and when he reached out to us earlier in the year, I did think he’d be handy to have at the back end of the season if we had any injuries,” Coleman said.

“It’s taken him a few weeks to fit into the team but on the weekend he was close to flawless. He kicked goals from everywhere, his tactical kicking was astute. He might not have as much zip as Hamish, but he’s a more physical defender and that could be important this weekend.”

But no matter who takes the field at just after 3pm on Saturday, Coleman said his message will be simple.

“We just need to go forward after contact in every aspect,” he said.

“When we’re carrying the ball, we need to go forward after contact and if we’re tackling, we need to stop them at the point of contact and drive them back.

“Our ruck speed will come off the back of that and if we can do that, we’ll be in the mix.”