The key tactic
The use of Jarrad Waite and Lachie Henderson
After starting the season in the forward line Waite played down back last week on Michael Hurley (who finished with three goals and nine marks). At his best Waite is a huge asset for the Blues down either end, but he's been struggling for form.
Henderson on the other hand has been a big asset since moving down forward in round 15. In the eight games he's spent down there he is averaging 2.5 goals a game (including two bags of four).
It will be an important decision for Mick Malthouse to decide whether he can afford to play both of them in the forward line.
Leigh says: "The last couple of weeks Waite is playing in defence and Henderson's playing forward. Early in the year it was the opposite.
"If you look at Port Adelaide, Jay Schulz is their main forward target and he's likely to be taken by Michael Jamison, who is the right match-up for him.
"I think there's a big chance that Waite could end up alongside Henderson and Levi Casboult in the forward line.
"I'm not sure whether Port Adelaide have got a good enough second forward outside of Schulz to make Waite play down back.
"Westhoff could maybe be that guy, so if he's there then Waite would be a good match-up for him, because in my opinion the next batch of Carlton defenders are just average."
The key match-up
Marc Murphy vs. Kane Cornes
Murphy has had a very disappointing year in his first season as captain.
His averages of 21.9 disposals, 3.8 clearances and 3.5 inside 50s are all his lowest in more than four years.
The Blues will be without Chris Judd and Andrew Carrazzo among others, so the dependence on Murphy will be significantly amplified in this match.
He has struggled with tags on an almost weekly basis and it won't get any easier with Kane Cornes likely to head his way.
Leigh says: "Marc Murphy has been tagged into mediocrity. I don't look a whole lot into the captaincy element, I just think that he's become Carlton's best midfielder and he's now the first guy getting tagged.
"Last week against Essendon he had 22 disposals, but there's just no effectiveness in his game, so it's going to be a massive challenge for him to be effective against Kane Cornes, who's a very good stopper.
Murphy knows he's going to have a tough tagging opponent and Carlton will need to work together as a team to make it hard for Cornes.
For the Blues to win they need Murphy to be a weapon for them and have a good game."
The last word
Port Adelaide to win
Leigh says: "I think I'll stick with Port. I know they had a shocker last week but they've been very good in Adelaide. So I'm going with the home team."
Round 23 tips
*Winner in capitals
Sydney Swans vs. HAWTHORN
St Kilda vs. FREMANTLE
GEELONG vs. Brisbane Lions
PORT ADELAIDE vs. Carlton
Essendon vs. RICHMOND
WEST COAST vs. Adelaide
GOLD COAST vs. Greater Western Sydney
COLLINGWOOD vs. North Melbourne
WESTERN BULLDOGS vs. Melbourne
