Essendon big man Shaun McKernan has been asked to fill the immense void left by Cale Hooker in Friday night's match against Sydney at the SCG.

Hooker, who is coming off a five-goal haul in the club's thumping of Port Adelaide, dislocated his finger at training this week and would be sorely missed in the Bombers' crunch clash with the Swans.

Hooker's replacement will be McKernan, elevated on Thursday off their rookie list.

The former Adelaide ruckman has played 17 games for the Bombers since joining the club in 2014. The majority of those have been in the ruck, including rounds one and two this season.

"Shaun McKernan has been in wonderful form in the VFL," Essendon coach John Worsfold said on Thursday in Sydney.

"He's a strong marking player and will play a very similar role to Cale.

"We're happy that we have a player who was in good form earlier in the year.

"He went out of the side because he was playing mainly as a ruckman, but he is a key forward and he's ready to go."

Meanwhile, Kyle Langford has claimed David Myers' place in the Bombers' side.

Key defender Michael Hartley is set to be given the onerous job of minding Lance Franklin, who boasts an incredible record against the Bombers.

Franklin has booted 64 goals in 13 games against Essendon, an average of 4.92 per game.

"He's played well in the past. I haven't seen the record, so haven't given it a lot of thought," Worsfold said.

"A lot of times, it (Franklin's opponent) depends on the role Buddy plays and how the match-ups pan out.

"But, no doubt Hartley will be matched up on him for a fair part of the night."

Worsfold is upbeat that Hooker, who has avoided tendon or bone damage, will only miss one match.

"He was still in the side at 10am this morning," he said.

"But when we reassessed him and had a look at him handling the footy, we didn't feel like he was going to be able to play at the level."