Mitchell Woodcock: Luke Jackson is Fremantle’s No.1 ruckman, but Mason Cox not convincing in back-up role

Fremantle’s ruck riddle is now a two-part question. The first — who is the No.1 man? The answer to that is more obvious than ever. Luke Jackson is now the main man in the middle. When the Dockers’ midfield was at their best in the western derby, Jackson was in the thick of things. Jackson’s ability to get first hands on the footy in the ruck contest and then apply pressure at ground level is second to none amongst the ruck ranks right now. The 24-year-old is simply the most invaluable player at Fremantle and if they’re going to win the premiership, he has to be the man who starts in the middle every week. And he is no one-trick pony. Jackson can go forward and take a mark, meaning he is easily capable of playing about 80 per cent game time. There has long been a concern that if he is left to be the main ruckman, Jackson will be beaten and bruised. That can no longer be factored in because Jackson is now the one capable of doing the beating and the bruising. This brings us to the second part of the riddle — do the Dockers play Sean Darcy or Mason Cox? And we’re no clearer on the answer. Cox had a great opportunity to stamp himself as a mainstay in Justin Longmuir’s outfit with Darcy sidelined with concussion. And while the 35-year-old didn’t do anything wrong, he just didn’t do enough right. Cox came on midway through the first term and had several almost moments. He almost took two marks deep in attack and then almost another big mark in defence. Once he settled into the game he did well in the ruck, but when the moment called in the second quarter he almost kicked a goal but missed. Simply, he didn’t do enough to convince everyone he should be picked ahead of Darcy for now. So the question at the feet of Longmuir is where does he go against Carlton next week? Does he back his first instinct which was to back Darcy in to continue the role he played for the first five games? Or does he give the big American another crack to see if he can build on what was maybe just first-game nerves? Regardless of which way Longmuir goes, it’s a great problem to have.