John Worsfold has challenged Matthew Leuenberger to win back his place as Essendon's No.1 ruckman after he was overlooked for selection this week.

The former Brisbane Lion has been the Bombers' first-choice ruckman this season but missed last week's loss to Richmond with illness and was replaced by Tom Bellchambers. 

Bellchambers, in just his second game of the season, had 40 hit-outs against the Tigers and performed well having also booted six goals in a VFL game before his call-up. He will take on Greater Western Sydney on Saturday when the Bombers travel to Spotless Stadium. 

The Bombers considered picking both big men for the meeting, but Leuenberger will play in the VFL this weekend and Worsfold said it was up to him to get back his spot having held the ruck role for most of the season.

"Obviously Tommy had an interrupted pre-season, so 'Leuey' was in there through being available and up and going and it was up to Tommy to stay in really good form and wait for opportunities, which he did," Worsfold said on Friday.

"Now the pressure's back on Leuey to win the spot back."

Worsfold backed Cale Hooker to hit form as he continues his transformation from brilliant defender to key forward, after a quiet game against the Tigers last week.

The Bombers will resist the urge to send Hooker back this week to counter the Giants' dangerous forward line.

"He'll play forward, but we were certainly having a look at options like that. At the moment, we think that our best forward line has Cale in it," he said. 

"Our forward line efficiency has been outstanding and the one game we won the inside-50 [count], we won by 10 goals. There's other areas we've got to improve to make sure that forward line gets more opportunities."

Emerging midfielder Darcy Parish will miss the clash after straining his quad at training, with Worsfold hopeful the 19-year-old will only miss two games and be available after the Bombers' bye, which falls in round 13. 

Parish's absence is unlikely to see the Bombers take a chance to blood No.1 pick Andrew McGrath in the midfield, though.

The club's first ever top pick has been excellent in his debut season across half-back, and gathered 26 disposals last week against the Tigers.

McGrath, who turned 19 on Friday, starred as a midfielder in the latter stages of his draft season and Worsfold said it was in the club's plans to use him there at some stage of his debut AFL year. But just not yet. 

"When that is, I can't answer. But it is part of our plan for his development, but we're going to stick to the plan we've got in that regard. I know there's some people who want to see him in there already, but they don't have a job here, so they'll have to wait," he said. 

McGrath is the favourite to take out the NAB AFL Rising Star award.