COLLINGWOOD coach Nathan Buckley has challenged his midfield to stand up in the absence of Luke Ball, who will undergo a season-ending knee reconstruction on Tuesday afternoon.

Ball made a surprising appearance at the Magpies' recovery session at St Kilda Sea Baths only hours before he was expected to undergo the knife on his right knee.

He also completed a gym session at the club on Monday.

He was in good spirits at the Sea Baths and even helped out with drills before the players entered the water.

Buckley put the responsibility on Sharrod Wellingham, Dayne Beams, Steele Sidebottom and Jarryd Blair to step up in the absence of Ball.

"He's a phenomenal individual. I can't stand here and tell you it's not going to hurt the club because a bloke with his character and with his football pedigree not out on the field is going to really challenge our structures," Buckley said.

"It's going to challenge the personnel that have existed around him for the years he's been at the club - it's an opportunity for [them]."

Buckley said Ball's attitude since Friday night's injury couldn't be faulted. 

"To come down here and be involved in our breakfast and recovery … he's a quality individual and we need to make sure we tap into his mentality, his mindset and football knowledge throughout the rest of the year, and we'll get him involved as much as we possibly can," he said.

Midfielder Ben Johnson told the club's website after the VFL side's seven-point win over the Northern Blues he felt "pretty confident" about his fitness ahead of Saturday night's clash with Port Adelaide. 

Nathan Brown was named in the team's best in his second game back from two knee injuries.

Buckley said last week he would need "three to four" hit-outs but Chris Tarrant and Ben Reid's unavailability creates a considerable defensive hole.

Club doctors will determine on Tuesday if Brown is match-fit before a decision is made.

Buckley said the Pies' four-day break ahead of the Anzac Day clash with Essendon would be considered when determining Brown's availability.

The prospect of him playing two games in four days is unlikely.

He said Alan Didak needed more VFL time after one game while Kirk Ugle, Simon Buckley and rookie Caolan Mooney impressed on the weekend.

Jennifer Witham is a reporter for AFL.com.au. Follow her on Twitter @AFL_JenWitham

The views in this article are those of the author and not necessarily those of the AFL or its clubs