Essendon champion James Hird says he was "shocked" by his son Tom's decision earlier this year to give up his soccer aspirations and join the Bombers as a category B rookie.

Tom Hird became a fourth-generation Bomber when he signed with the club in March, leaving a burgeoning round-ball career to follow in the steps of his famous father.

He had trained with Essendon ahead of the 2019 season through the club's pre-season program before trialling for soccer in the Netherlands, but the lure of the Bombers was strong.

"I think Tania and I were both pretty shocked actually that he chose to go down this path. He'd been going very well at his soccer both here and overseas, so we were a bit taken aback that he wanted to go down that path," the former Bombers great and ex-coach said on club podcast Working Through It.

"He and [Essendon list manager] Adrian Dodoro must have been concocting some sort of plan without us knowing, so we were a little bit shocked but now he's down that path we're fully supportive.

"He's training very hard. It's interesting to get a look at what he players are doing now and the way they need to train, and the club's been very good at setting up a structure for him.

"What I've been very impressed with is not only the physical side of things, but the psychologist's been in touch with him a fair bit and also with Tania a fair bit." 

Tom, who agreed to a two-year contract, is the fourth generation of his family to join the Bombers, following his father James, his grandfather Allan and great grandfather Allan Sr, who had a grandstand at Essendon's Windy Hill headquarters named after him.

He is a small left-footer who could be used in defence or attack, and was only early into his time at the club before it was shut down to deal with the spread of the coronavirus.

Hird joked he may soon have to muscle in on Tom during a marking contest, "because he's getting very confident with his new body" after joining the Bombers.

"He's got a long way to go and hopefully he does well, but obviously there's a lot of hard work in front of him, but the good thing is he's a hard worker. He's got a lot of support from his family and the club so we'll see how he goes," he said.

"I think he got two or three weeks down there but I think he's enjoying [it]. A footy club is a great place to be and the one thing you have to admire football clubs for is they put a lot of time into their players and genuinely care. It's great to see."