INJURIES happen.

But some hurt more than others.

West Coast and Collingwood understand that right now.

The Eagles go into round 17 without Jeremy McGovern and the Magpies do so without Travis Cloke.

Both are key planks in the clubs' structures at either end of the ground.

Cloke, and the Magpies' other notable absentee Jamie Elliott, have kicked 60 of the Magpies’ 206 goals this season. Between them they are the targets inside 50 on average about 10 times a game.

McGovern is second in the AFL for intercept marks (averaging 3.8 per game), behind the Western Bulldogs' Easton Wood, and has been critical in the Eagles holding up so well after losing both Eric McKenzie and Mitch Brown to season ending knee injuries.

So how do you cover for them?

The question facing both West Coast's and the Magpies' coaching groups is similar but the answer may well be different.

Do they plug a replacement into the role the injured player held or should they attempt to create a completely new look to confound the opposition, with the risk they cause more confusion among themselves?

The Eagles look likely to shuffle the decks, pushing Elliot Yeo back and shifting Shannon Hurn into a more defensive role. Tom Barrass may have a role to play but no one will be expecting the youngster to replace McGovern.

Adam Simpson will look to each member of the team to share the load from front to back. He won't move forwards back.

He'll ask the Eagles to move forward as a group, working together with a plan that protects the undersized back six.

Most expect the Magpies to introduce the inexperienced Darcy Moore, Corey Gault or Jonathon Marsh into the line-up to replace Cloke, but the club could consider shuffling roles to create a different potency inside 50.

The Magpies could take a lead from Hawthorn, which has the most potent attack in the competition, and rotate a variety of mobile players through their forward line.

The Hawks have five players who have kicked between 36 goals (Luke Breust) and 19 (Paul Puopolo), with flexibility at the club a must from the moment 'Buddy' Franklin put off contract talks early in 2013.

The Hawks use a rolling set up that is dependent on the way the game is being played and what the opposition throws their way. Matt Suckling has been used forward more often this season with Brad Hill and Isaac Smith on tracks up and down the ground while Jack Gunston is an everywhere man. They average more than nine goalkickers per game.

Shannon Hurn is likely to take on a more defensive role for the Eagles. Picture: AFL Media

To become the best transition team in the competition, as they aspire to, the Magpies must use Cloke's loss as opportunity to plan for the future.

It will take nerve as the Magpies need a win, but they also need a plan that makes them better in 12 months time.

To do that the Pies must rotate players such as Scott Pendlebury, Dane Swan, Ben Kennedy, Adam Oxley, Steele Sidebottom, Jordan De Goey and Levi Greenwood through their forward 50 alongside Jarryd Blair and Alex Fasolo.

Jesse White will face scrutiny but his role will be to get on the move and do what he does well, which is lead up to the ball. Playing second fiddle to a huge presence such as Cloke is not always easy, and despite having many doubters, White has kicked 21 goals in 2015.

The Magpies could also surprise by moving Jack Frost or Nathan Brown forward, and give Matt Scharenberg a chance to debut across the half-back line.

Melbourne's Tom McDonald kicking two goals against the Brisbane Lions and Cale Hooker taking 13 marks (five inside 50) for the Bombers against North Melbourne are good examples of defenders in recent weeks who have had an impact up forward.

When the Magpies and Eagles met in the NAB Challenge, the Pies struggled to move the ball from defence and also battled to convert when inside 50.

McGovern's injury is a blow for the Eagles that they will manage as best they can.

Cloke's injury is an opportunity for the Magpies to develop. If the Magpies are brave enough to take it.