A battler - a person who battles or fights, who refuses to admit defeat in the face of difficulty.

These are traits that every AFL player should strive for and they've been evident throughout Glass' 270-game career, right down to his last game.

And they are the traits that will see Glass' appointment as captain of the Eagles in 2007 go down as one of the best decisions the club ever made: as he became a crucial leader of a club at an important time in its history.

In the end, ankle and hip injuries, that he has carried longer than this season, made it too difficult for him to recover between games.

He says he played on one year too long, but with a change in coach during the summer, having a stable leader in place for young players to look up to was important.

"[I'm] a battler mate. It's called a scragger, I think. I just defended like a defender should defend - desperately," he said when announcing his retirement on Thursday morning.

"I had my limitations as a player, but loved playing the game, loved competing.

"I'm not confident of playing any decent and good consistent footy in the back half of the year and feel like it's time to step aside.

"With hindsight I've probably played a year too long."

He saw the writing on the wall as early as round four of this season when he couldn’t get up for the game against Geelong, when Dean Cox broke the games played record for the club.

Despite the club trying to talk him into playing a farewell game, in his true selfless style he declined, not wanting to steal a game from someone else.

Not that his form can be questioned; just look at the replay of his performance in the round 10 loss to Collingwood at the MCG. His best is still good enough, Glass just feels that he can't reach his best often enough now.

Just how good was Darren Glass?

Statistics can't be used to determine the impact of a key defender. He had 20 possessions or more in a game only seven times in 270 outings; and he kicked only eight goals. His last major came against Richmond in round five of 2007 at the MCG and was the only six-pointer he didn't kick at Subiaco Oval.

Still Glass is sure to be one day inducted into the game's Hall of Fame. He finishes with three Eagles Club Championships, a premiership and four All-Australian selections, including once (2012) as captain.

But for club CEO Trevor Nisbett, his value to West Coast is far more crucial than awards and accolades.

Glass took over as captain in 2007, after Chris Judd returned to Melbourne and after Ben Cousins was so controversially given his marching orders. Many incidents over many years had the entire competition questioning the culture of the boys in the west - despite them just having won a flag.

Changes needed to be made and Nisbett sees Glass' appointment as captain as being integral to them being able to do so.

"He was the lynch pin," Nisbett said.

"If he didn't buy in to what we were trying to do, you don't have any chance if your leader doesn't buy in and he was the first one to put his hand up and say, "I'm in, we need to change this. We have to change the culture that we had".

“It took us three or four years to do that. Cultural change is probably the most difficult thing. He has now left a legacy," Nisbett said.

Nisbett said that he expected that Glass would have continued on, depsite his injuries, had he not thought the playing group had moved on from those dark years.

That legacy is something Nisbett hopes will linger in the Eagles' changerooms for a long time, as the club continues to rebuild.

"He's a bit better than just a scrapper," he said.

"I think the other thing he has done in his 270 games is when he started he couldn't get a game, he was skinny kid from Perth, really struggled with coming in and out of the team and he had opportunity to move elsewhere and he chose to stay and work his way into the team.

"I don't think it was until his fourth season that he started to play regular footy and he relayed that to the players today.

"I think he has always said that you have to work through the challenges and he's been a part of a cultural change which I think puts him further up in the estimation [in the list of influential people at the Eagles] because he led the charge and he realised that we were going to have some dirty days and tough years on field because the change in culture that he had to help with."

The Eagles have not made a decision on who will captain the side for the remainder of the season.

Coach Adam Simpson hinted on the players rotating to role for the last 11 games and then starting fresh in 2015.

Simpson only coached Glass for eight games, but has no doubt as to the reputation Glass leaves the game with.

"I spoke to the players earlier today about perception about players and the perception of Darren has been not a bad word spoken about him," he said.

"He's an All-Australian captain as a key defender. How often do you see that? That speaks volumes of where he's held, not only in the club, but across the competition.

"And to be captain too. How many key defenders are captain. Not just three or four years, but seven years as a captain. He's a legend of the club."

Yep, as Glass turns the lights off on his career, he can take one look back over his shoulder and see just how much of a battler he truly was.