ESSENDON will use its final two NAB Challenge games to decide if it will upgrade any rookies to replace its 12 suspended players.

Under the AFL's rules the Bombers were able to sign 10 top-up players to their senior list to cover for the banned dozen.

But they were also permitted to upgrade two rookies to the senior list, just as if any of the suspended players had been put on the long-term injury list.

Last week the Bombers played four rookie-listed players – Anthony McDonald-Tipungwuti, Will Hams, Conor McKenna and Jake Long – in their strong pre-season win over Carlton.

Essendon football manager Rob Kerr said the club would wait to see how the rest of the pre-season competition unfolded before making any decision on its list.

"It's going to depend on form. With the rookies the ruling gives us the ability to elevate two players at any time as if there was a long-term injury, so there's no rush from our end," Kerr told AFL.com.au. 

"If someone's form was such that they commanded a place in the team then we'd elevate them then. If someone was pressing a claim for a senior spot in round one we'd certainly elevate them."

Revealed: The 2016 Bombers' list

Kerr said the rookies who took on the Blues last week "all contributed" but nominated 22-year-old running defender McDonald-Tipungwuti as the leading candidate at this stage.

"Probably McDonald-Tipungwuti has done more at this point, but there's still two games to go and those other boys will get their chances," Kerr said.

"Then it's a question of 'Do they push someone else out as well?' They've had pretty good pre-seasons and put themselves in a good spot."

All four of the club's fit rookies have again been selected to face Geelong on Saturday in the Bombers' second NAB Challenge clash, with fellow rookies Tom Wallis and ruckman Gach Nyuon unavailable.

While the Bombers may enter the season with 38 senior players if they choose not to upgrade any rookies before round one, they last week added Sam Michael as their 10th and final top-up player for the season.

Essendon had toyed with signing just eight of the possible 10 top-ups, but Kerr said the value brought by Michael and former North Melbourne defender Nathan Grima was too strong to pass up.

"We always thought we were a key defender short, so we were going to fill that with Grima," Kerr said.

"Sam Michael had been training for a few weeks and the conclusion we reached there was to regard him more as a ruck option as opposed to a key-position player. 

"Once we got our heads around the way he trained and applied himself as a ruck in some of the trials, we thought he's not a bad back-up."

Will Hams is among the Essendon rookies hoping for a senior upgrade. Picture: AFL Media