A STRING of injuries during Essendon's 59-point loss to Port Adelaide didn't cause the costly defeat but they certainly didn't help, coach John Worsfold has conceded.

Versatile forward-ruck Shaun McKernan was a late withdrawal with illness before the game started, but it was defensive duo Adam Saad (hamstring) and Aaron Francis (several knocks) as well as midfielder Darcy Parish (concussion) that caused in-game headaches.

Adam Saad (right) was hampered during the loss to Port Adelaide. Picture: AFL Photos

The loss of McKernan pre-match also altered Essendon's tall stocks all over the ground, especially considering No.1 ruck Tom Bellchambers (calf) is still several weeks away. 

Cale Hooker was due to start in defence but was forced to play mostly forward, where he failed to trouble the scorers.

"We had to use Mitch Brown more in the ruck, which takes him out of the role he's been playing really well (forward)," Worsfold said. 

"We had to adjust to that, but we've done that in the past and been able to cope, so that wasn't a big reason. [But] it doesn't help."

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Worsfold said Saad and Francis played the game out under duress, while Parish will be assessed ahead of next week's clash with the Western Bulldogs. 

Aaron Francis in action against the Power. Picture: AFL Photos

"We were juggling that a little bit. We obviously had Parish out of the game, we were assessing Saad to see how he was tracking, and Francis got a couple of knocks, I think in that third quarter," coach John Worsfold said.

"Saad was a tight hamstring. They assessed him just before half-time, we said we'd leave him off and assess him [again] at half-time, and the assessment came that it was just tight, and he was OK to go on. 

"A bit of a heightened risk, but he didn't have a strain there. He did really well to get through the game, we took him off with 10 or 15 minutes to go and left him off from there, just for precaution."

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The Bombers were coming off five straight wins, but only just fell over the line against the battling Gold Coast last week, in what Worsfold said was potentially a sign of things to come against the Power.

"We were well off the level we've been playing at. Mind you, last week we were a bit off, we were a lot further off this week," he said.

"We were beaten around the ball, clearances, contested possessions and ground balls. Didn't take our opportunities earlier in the game, could have put some more heat on them. 

"In the first half, it was pretty even, they took their chances, we didn't, which gave them a couple [of] goals lead at half-time. But it really came down to that third quarter, we fell away and didn't match them at all."