A freak accident means All-Australian Harry O’Brien will be the latest Collingwood star to miss the opening round of the AFL pre-season cup.

O’Brien put his hand through some glass, leaving him with stitches in his little finger.

Coach Nathan Buckley said O’Brien would only miss Saturday night’s round-one games against Greater Western Sydney and the Western Bulldogs at Blacktown.

Alan Didak (adductor), Ben Johnson (hamstring) and Andrew Krakouer (personal issues) are already out for most of the pre-season games.

“He put his hand through a pane of glass at home, so we can’t take a trick at the moment,” Buckley said of O’Brien.

“Harry has a few stitches in his little finger and will miss this week and will be right for (the second week of pre-season competition).

“We’ve had a few of those `away from training’ injuries that have bobbed up.

“It’s just a freak accident, as far as I know.”

Buckley added there was “nothing untoward” about O’Brien’s accident.

The new Magpies coach said they would take a smaller squad to Sydney and “four or five” players would make their Collingwood debuts.

“Given we have a couple of weeks on the other side of this game, it influences … the people we want to take up,” Buckley said.

“We’ll see a lot of youth, there will be a lot of opportunity … for blokes to build on their leadership opportunities as well.

“We’ll have a few leaders out.”

But Buckley said there would be excuses for the `Pies and they expected to win every time they played.

He is looking forward to his debut as the full-time senior Collingwood coach and said he was not feeling any nerves yet.

“For me, it’s a chance to dip a toe in the water and (for) the rest of our coaching staff, to make sure our systems are in place and ready to go (in) round one,” Buckley said.

Buckley expects the Giants to be tough opponents in the pre-season, noting how keen Gold Coast were to make a strong start when they made their AFL debut last season.

“We saw with the Gold Coast as well, they were one of the better clearance sides in 2011 – we expect a similar type of football,” he said.

“Obviously with Kevin Sheedy and Mark Williams at the helm, there’s probably going to be a fairly strategic game style used as well.”

Meanwhile, Buckley has backed Krakouer after the small forward was given a month off to deal with personal problems.

“We’re in constant contact with him (and) we’re going to support him through this period,” he said.

“There are things at the moment that are preventing him from training as often as we’d like.

“He’s going to use that month to get back on his feet.”

Asked how confident he is that Krakouer will return to the club, Buckley replied: “I’m 100 per cent confident he’ll have every chance to do that.”