Adelaide's ruck division took another blow on Thursday when No.1 ruckman Matthew Clarke announced his retirement from AFL football.News of the 33-year-old's decision came one day after the Crows lost fellow ruckman Rhett Biglands who will undergo a knee reconstruction and miss all of next season after injuring his knee in last week's preliminary final loss.Clarke told a media conference on Thursday that he thought twice about his future after Biglands' injury."I played out this year with the intention that it would be my last, and that's the way I came off the ground last weekend," Clarke said."The situation with Rhett did cause me to sit back and say, 'what's going on here?', but, in consultation with the club and Neil, we felt it was probably best - while that may be a safe option - that in some regards it's time to show some faith in the young guys we have drafted over the last couple of years."Clarke said he didn't want to play one season too many."I have seen that, and that did weigh into my thinking somewhat," he said."Unless you are able and willing to make that commitment, which becomes increasingly difficult each year, then I think you are best to stand aside and let someone else have a go."I think I was ready. It was not particularly difficult. I am sure down the track I will miss it, but I have had a good run. If Neil had asked me to go on, it would have made it more difficult. We had a good open chat and I am comfortable with it."Clarke played 248 games in a career that started back in 1993 with Brisbane where he played 130 games and took out the club's best-and-fairest award in 1997.The former Mount Gambier native returned to his home state when Adelaide traded pick number six to the Lions at the end of 1999.Clarke's deft tapwork proved an excellent foil to the more bullocking style of Biglands with the two carrying the bulk of the club's ruck duties over the past seven years.Clarke enjoyed something of a renaissance this season, displaying some excellent form in 18 games after a disappointing 2005 that saw him play just six games.The 200-centimetre ruckman played four state of origin games for South Australia during his career.Adelaide CEO Steven Trigg paid tribute to Clarke's "outstanding service"."It's a somewhat poignant day when one of your great servants decides to retire, and Matthew has been a hell of a good bloke at the same time," Trigg said.The absence of Clarke next season leaves Adelaide decidedly inexperienced at the position. As it stands, the club will go with fourth-year ruckman Ben Hudson - who missed all of 2006 recovering from his own knee reconstruction - and eight-gamer Ivan Maric or the untried John Meesen.The Crows could well enter the 'Peter Everitt Stakes' should the need for an experienced replacement for Clarke be deemed a priority by the club's brains trust.On the prospect of trading for Everitt or Michael Gardiner, coach Neil Craig said: "I have not spoken to them.""I do not know what their availability is. What I will say is that the charter of our football club has not changed from two years ago, which was to try to play some winning football, and, in conjunction with that, to make sure we stick to trying to build our playing stocks with younger people. I think it is the way to go, so it is unlikely."