Essendon coach James Hird admits his side’s gruelling training load may have contributed to a rash of soft tissue injuries, including three in the AFL win over Port Adelaide on Saturday.

The Bombers beat Port at Etihad Stadium to maintain their unbeaten start to the season but the personnel toll was high – ruckman David Hille, defender David Myers and utility Nathan Lovett-Murray all limping off with injuries.

Hird expects Hille, who has a calf injury, and hamstring concerns Myers and Lovett-Murray to miss between two and four weeks.

Added to midfielder Jason Winderlich’s breakdown at training last week with a hamstring problem, and Hird believes a heavy workload – which he makes no apologies for – may have contributed.

“It’s every possibility we’ve gone a little bit hard, but we need to find that balance with our players,” Hird told the Seven Network’s AFL Game Day.

“You don’t become a good side by under-training. You’ve certainly got to take them to the limit … but we’ll recover those guys.”

Most concerning would appear Winderlich’s latest setback.

After a serious knee injury sustained in round four last year, Winderlich was on the verge of returning before trouble with a hamstring.

Best case scenario is when the 27-year-old does return, he will have not played top-level football in a year.

“Jason’s hamstring where he had the graft is not going as well as hoped,” Hird said.

“His knee’s fine. But his hamstring’s not reacting as well as we’d like. So he’ll miss another couple of weeks.”

Collingwood look set to lose key defender Chris Tarrant for at least a fortnight after he limped out of the Magpies’ win over Richmond on Saturday night just minutes after his return from injury.

Tarrant has a calf problem.

Scans are likely to determine the fates of West Coast veteran Andrew Embley (shoulder) and Richmond forward Jake King (knee), who also suffered weekend injuries and could miss several weeks.

But the Western Bulldogs believe defender Ryan Hargrave may be fit to play this weekend after jarring a knee in Saturday night’s 18-point loss to Adelaide.

Fremantle defender Paul Duffield has also been cleared of a collapsed lung and broken ribs after he was rushed to hospital in his side’s loss to Sydney on Saturday.