AFL umpires’ coach Hayden Kennedy was an interested onlooker at Collingwood training on Tuesday, as the Magpies went through final preparations for Thursday night's clash with Adelaide.

Kennedy came to the training session of his own accord, and assisted the Magpies in understanding some of the different umpiring interpretations.

Magpies coach Nathan Buckley said he and Kennedy engaged in some positive dialogue in the umpire’s half-hour stint watching training.

The unscheduled appearance from an experienced field umpire came on the day Melbourne coach Paul Roos called for a regular update from the League’s umpiring department on decisions that are causing confusion to players.

"We were keen to take the opportunity and I think this is a fantastic initiative by the umpiring department to maintain those relationships," Buckley said on Tuesday afternoon.

"We seek continued clarity about how the ruck interpretations are progressing, in marking contests and the holds around clearances."

Buckley has already sought clarification from the umpiring department early this year about Brent Macaffer's tagging techniques.

The Magpies’ coach said Kennedy's presence allowed him and his staff to keep the playing list up to date on the different trends and interpretations in the game.

"Having a bit of feedback from the other side and how it's looking from an umpiring perspective is important for us to make sure we've got the one percenters right, to give ourselves the best chance of performing," Buckley said.

During the two-hour training session at the Olympic Park Oval, Nick Maxwell, Alan Toovey, Clinton Young, Alex Fasolo and Sam Dwyer all proved their fitness for the club's meeting with the Crows at Adelaide Oval.

Now it is a case of finding the right team dynamic and considering the option of making four or five changes at once, according to Buckley.

"We've got a squad of senior personnel who are putting their hands up," he said.



"The four guys who missed last week (round seven) have basically passed fitness tests and are clear to play," Buckley said.

"We've probably got a squad of 28 or 29 players who would have claims on playing on Thursday."

Buckley said his side needed to be careful not to change its squad too much, but instead find the right "balance" when making changes.

Over the bye round, Buckley's review identified two key areas for Collingwood to improve on heading into the second half of the season.

The Magpies are ranked last in the competition in both kicking and disposal efficiency (68.1 per cent), which Buckley singled out to his players over the break.

Offensive and defensive improvement was a must, the coach reiterated.