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