Even though Thompson coached Geelong to the 2007 and '09 premierships, he is unsure about how he will perform.

Essendon opens its season on Friday night against fierce rivals North Melbourne at Etihad Stadium.

"I (am) a little bit nervous, but excited as well," Thompson said on Tuesday.

"You just don't know how you're going to handle it - you know you've done it before.

"But every time it confronts you, you just say 'I wonder if I've still got it?'

"Then you find out, I suppose."

While suspended coach James Hird is bullish about the Bombers' chances this year, Thompson said the players must learn how to look after themselves better during matches without his immediate guidance.

It is already another season of uncertainty for the Bombers, with the club still under ASADA investigation for its 2012 supplements program.

There is no word on when ASADA will decide whether it issues infraction notices.

Hird is serving a 12-month AFL ban stemming from the supplements scandal and Thompson has taken over in the meantime.

Thompson said Hird's absence makes no difference about the aims for the team this season.

"What we're trying to do is get the players to really understand why and how they play, so they can read the game and make decisions on the ground for themselves that we don't have to make up in the box," Thompson said.

"That's a fair bit of work.

"It might sound easy, but to give the players the confidence and the courage to control what they do out on the ground is a big thing."

The Bombers had an indifferent pre-season with no wins and most recently looked flat when Richmond beat them easily two weeks ago.

"We made a conscious decision to train them and sometimes when you do that, you don't get the results you're looking for when you start playing," Thompson said.

"We couldn't have kept training them and let the team play the way we have, so we've freshened them right up.

"Hopefully they've got a lot of spark, a lot of energy, a lot of speed and endurance, and they play some great footy."

Friday night also marks the 379th senior game for Dustin Fletcher, meaning he breaks Simon Madden's club record.

Fletcher is fourth on the AFL games list, only five behind St Kilda great Robert Harvey, and is entering his 22nd senior season.

Thompson was on the way to becoming an Essendon premiership captain in 1993 when Fletcher made his AFL debut.

"He walked in with a pair of shorts, a school bag and a school tie," Thompson said.

"He was 17, so skinny and pasty - it's incredible.

"He had a lot of goals kicked on him, but there was something there and Sheeds (legendary Essendon coach Kevin Sheedy) obviously found a gem."