IN THIS week's Nine Things We Learned, we discover the Dees have a huge decision to make, Hayden Young should never play in defence again plus much, much more.

Check out what we learned from round 21 of the 2023 season.

1) The AA selectors can't overlook James Sicily this year

Tom Stewart missed four games due to suspension (plus a fifth due to injury) in 2022 and still made the All-Australian side, and James Sicily should repeat that feat in 2023. The Hawthorn skipper produced another defensive masterclass on Saturday, this time terrorising Collingwood with 37 disposals, 19 marks, 11 intercept possessions, three goal assists and 515 metres gained at the MCG. Sicily was overlooked by the All-Australian selectors last year despite winning the Peter Crimmins Medal, but that shouldn't happen this time around. Sicily's best games have resulted in Hawthorn wins and when he missed three for that tackle on Hugh McCluggage – plus the week for a bump on Anthony Caminiti – the Hawks were smashed. There are plenty of great key defenders in the AFL, but not many are better than Sicily. - Josh Gabelich

2) In-and-out Blue still has plenty to offer

Out-of-contract midfielder Paddy Dow made a statement on Sunday, producing his best performance of the year to show Carlton he still has plenty to offer. The oft-maligned third overall pick from the 2017 draft has been linked with an off-season move, having struggled for AFL opportunities in 2023. Sunday's clash with St Kilda was only his seventh game of the season, five of which have come as the sub, and he only won his spot after Sam Walsh, Adam Cerra and Matt Kennedy missed out due to injury. But the 23-year-old delivered with 22 disposals including seven clearances, 10 contested possessions and the goal to put the Blues ahead in the final quarter. It remains to be seen what role Dow plays when the aforementioned trio of midfielders return, but Sunday's performance was exactly what the Blues needed to see from him - and could just increase his value on the trade market - Ben Somerford

3) The Kyle Langford debate is well and truly over

Kyle Langford's performance against West Coast on Saturday should put all discussions to rest: he's a forward. Despite playing in virtually every position on the ground across his nine seasons in the AFL, the 26-year-old has come alive in the Bombers' forward line this year even though he spent the pre-season training as a defender. Against the Eagles, he kicked five goals for the second week in a row - and the third time this season – to move into equal seventh on the Coleman Medal leaderboard. While he's also a good defender, his ability to impact a game in the forward line is invaluable, and the Bombers would be doing themselves a disservice if they reverted to using him as a Mr Fix-It around the ground. Langford has shown he can literally win games off his own boot and he'd be close to All-Australian selection as a forward this year. – Sophie Welsh

4) Don't forget Hayden McLean in Sydney's post-Buddy world

Sydney has had plenty of games in the past few years to see what life would be like beyond Lance Franklin, but Saturday night's win over the Giants was the first true test following the superstar's retirement. And while Joel Amartey turned heads early with two quick goals, it was Hayden McLean who stole the show with a bag of four in the Sydney Derby win. McLean's big night, which also included three contested marks and the clever assist for Chad Warner's match-sealing goal, continued a promising season. The 24-year-old is not the most high-profile player in the League, but coach John Longmire is in no doubt of his value. "He's got a big tank and can play a couple of different roles," Longmire said. "Whether we've had other players available or not, we've kept going with him because we think he's got something to offer. He's kicked goals, he's been able to go in the ruck – pretty handy, those type of players." – Michael Whiting

5) Hayden Young's future is in the midfield

Fremantle's backline started to sense they'd be losing Hayden Young permanently after his run-with job on Patrick Dangerfield in round 20, when he held the Brownlow medallist to 16 disposals and three clearances. After he turned defence into attack against Brisbane, Young's move now appears a formality. Young was outstanding in the first half against the Lions, starting in an accountable role against Lachie Neale but quickly generating plenty of forward forays with 15 first-half disposals, four clearances and four score involvements. He finished with 29 touches, six clearances and five score involvements, adding the big-bodied presence the Dockers have needed in their on-ball unit. With Corey Wagner slotting into Young's backline role, the Dockers can continue to look at Young in the midfield. It's hard to see him going back now. – Nathan Schmook

6) The young Crows defence is standing up

With Tom Doedee, Jordon Butts and Nick Murray all out for the year, the Crows have needed some new faces to stand up down back. And the undermanned defensive group has done so admirably, holding the Suns to just nine goals on Saturday in a win that keeps their season alive. James Borlase (who debuted against Gold Coast) and Irishman Mark Keane have been added to the mix in recent weeks, while youngsters Luke Nankervis, Josh Worrell and first-year star Max Michalanney have shown their ability at the level. The Crows will no doubt hope their leading defenders are back as soon as possible in 2024, but the new breed have shown they can do the job in the meantime. - Martin Smith

7) Petty-less Dees have a big decision to make

Just when the Dees' forward line seemed settled, they're now confronting another selection headache. A foot injury to Harrison Petty will create a vacancy in the forward line, and with the likes of Brodie Grundy and Ben Brown waiting in the wings, Melbourne has to figure out whether to revert to a dual ruck plan or persevere with a pure forward who can pinch hit in the ruck when needed. Petty kicked six goals last week and seemed on track for another important contribution against North Melbourne, kicking two before being subbed out of the match. Not only is losing Petty a blow to the Dees' firepower – they tend to win in matches when he plays forward – but his absence creates a conundrum for the Dees as they're forced to tinker with their structure heading into a crucial stretch of the season. – Sophie Welsh

8) Liam Jones could be key to a Bulldogs surge

Most of the focus from the Bulldogs' huge win on Friday night centred around the irrepressible Marcus Bontempelli and their lethal forward line, but the game of Liam Jones should not go unnoticed. The Dogs defender was in All-Australian form before he broke his arm in round 14 and his return could not have come at a better time for Luke Beveridge. With Josh Bruce out for the season and Ryan Gardner, Sam Darcy and Alex Keath also sidelined due to injury, the Dogs were in desperate need of some height, class and polish down back. Jones produced all three against Richmond, finishing with a team-high 10 intercepts, in a timely reminder of his quality with finals just around the corner. - Martin Smith

9) Port needs that top-two finish

A month ago, Port Adelaide was in a two-horse race for top spot, but after four losses on the trot – the latest against Geelong on Saturday night - it appears less than likely the Power will have the security of two home finals. Without a September victory away from home since 2014, Ken Hinkley needs to find a way to get back in the winning habit and it needs to start against the Giants next week. Injuries and illness haven't helped a difficult draw through the closing weeks, but excuses can't be traded for premiership points. And without the advantage of playing at Adelaide Oval, the 2023 flag will be mighty unlikely to fly there next year. – Howard Kimber