In a recruiting story with a nice touch of symmetry about it, the former Adelaide key forward and ruckman on Wednesday was picked up by the Bombers in the rookie draft, having been delisted by the Crows after six seasons and 34 games.

McKernan had effectively been squeezed out of a spot in Adelaide's best 22 by the rapid emergence of Josh Jenkins, who previously had also been a rookie list player for Essendon, and himself squeezed out of senior contention by too many rivals.

The pair have now effectively traded places. Not that McKernan, publicly unveiled as a Bomber only a few hours after his name had been called, had had time to ponder the irony. "I hadn't thought about it at all this morning, but now you mention it, I guess it is," he smiled.

And while Jenkins at this stage clearly has the better of the deal, entrenched on a senior list with a bright future, McKernan, who has spent the past fortnight training with St Kilda, at least has earned another crack at changing that.

"There's no doubt I'd rather be in his place, but I'm happy to come to a club like Essendon. Look at the amount of big games you get to play. I'm just proud to be part of the club," he said.

McKernan might also not have quite the same long queue of big men ahead of him for a spot as Jenkins once did.

When Jenkins left Essendon at the end of 2011 without having played a senior game, his path had been effectively blocked by the presence of David Hille, Paddy Ryder and Tom Bellchambers in the ruck, while up forward the Bombers still had hopes for Scott Gumbleton and a couple of promising youngsters in Michael Hurley and Jake Carlisle.

Three years on, the Dons still have plenty of talls, Joe Daniher now an essential part of the mix. But in the ruck, Hille is long retired, Ryder a controversial departure, and Bellchambers coming off an injury-riddled year, with only former Greater Western Sydney's Jonathan Giles for back-up.

But McKernan knows he is going to have to produce more consistency to grab any opportunity than he did at Adelaide, where by his own admission he was "up and down".

"I think I had some good moments and bad moments," he said. "I look back and 2011 was my best year, playing 16 games, and probably since then I've just fallen out of the side.

"I think my best is more than capable to play at the level, it's probably just those patches of bad moments I need to get out of my game. There are things I want to put in place to make sure I can be a better, more consistent player. I know my time is now."

McKernan is 17 years younger than older brother and dual North Melbourne premiership player Corey McKernan, who he says fully appreciates another touch of irony about his sibling ending up at the Roos' great foe of the late '90s and early 2000s.

"As you can imagine, Corey doesn't have much love for Essendon, but he's still happy that I'm here," he said. "He's just rapt that I've got another chance. He said to me: 'Now you've got a second chance, you don't want to get in this position again. Just make sure you leave nothing unturned and give it everything you've got'."