Birchall has missed most of the season with injury, as have fellow backmen Trent Croad, Rick Ladson, Stephen Gilham and Brent Guerra.
Luke Hodge is the only member of last year’s premiership-winning back six to have played every game this year, but even he is struggling with an adductor injury.
“Five of our defenders from the premiership team haven’t played for the last couple of weeks. It is hard. You want some stability in your back six,” Birchall said.
“We haven’t really had that this year. In saying that, it gives some guys good opportunities. Tom Murphy has stepped up this week. Brendan Whitecross and Beau Dowler are starting to play regular footy across the backline and are getting some exposure. From that point of view it is a positive.”
Birchall made his return from a thumb injury in last week’s loss to Essendon. He gathered 28 possessions and was one of his side’s best.
He admitted he did not cope well with sitting on the sidelines and watching on.
“It felt good to get back into it again after missing three weeks and watching the boys from the stands. It isn’t much fun and I wanted to get out there,” he said.
“When you’re not playing you really want to get out there and help the boys. If they get beaten it is even worse. It is pretty hard to take. That is footy I suppose. You get injuries and different things happen every week and you have to deal with it the best way you can.”
Birchall labelled this Friday’s match against Fremantle as crucial as the Hawks look for a spot in the top eight.
“It is a crucial game for us. You don’t want to go 3-5 and be behind the eight ball. It is a really important game,” Birchall said.
“They are in good form and have won three in a row. Their confidence is going to be up and it is never an easy task going over there and trying to beat Freo. We are expecting a tough contest.”
