Chapman, who played under Thompson at Geelong from 2000-2010, including two premierships, crossed to the Bombers at the end of last season after the Cats decided not to offer him a new contract.
The champion half-forward has settled in well, and Thompson has noticed the 32-year-old is much more vocal than during his illustrious career at the Cats.
"Chappy's influence around the club has been interesting. He never really was someone who spoke that much at Geelong, there was already enough people who did speak," Thompson told AFL.com.au.
"Coming here I think he's really enjoyed the challenge and the inquisitive nature of some of our players and supporters about his knowledge. He's probably talked more than I've ever heard him talk in the short time he's been at the Bombers.
"On the track he's been going really well and people are just astounded by his skill. He gets the ball, he doesn’t run too much, and he just knows where to run and knows what to do with the ball.
"What he's been saying has been really helpful for some of the players."
The 251-gamer, who is Essendon's second oldest player behind veteran defender Dustin Fletcher, joined the Bombers because he believed they were in contention for a premiership.
Thompson said Chapman's view had been reinforced since joining training.
"Once he's been here he's really been pretty happy about the playing list and how we've been training.
"It's certainly not as good as the peak of Geelong, but I think they're really serious about what they're doing, he sees, they want to get better, they want to push up into the finals, they want to be a good team, and hopefully win a premiership.
"I think he's pretty happy with that result."
Tom Bellchambers' serious ankle injury spoiled an otherwise strong pre-season for the club.
But Thompson said his players were not using last year's disappointment of being banned from playing finals as a driving force.
"The team were resolute in 2013 and you expect that from most good young groups. I don't think anything should change.
"I don’t think they should be really motivated to play football. It's what they put so much time and effort into and they're elite players, so I don't think they really need any intrinsic motivation to get them up.
"Missing finals was hurtful, but they were just the cards that were laid at the time. This year's another year and we're moving on.
"We've trained particularly well, changed it up a little bit, trained really intensely, the players are enjoying it, they're starting to really coach themselves on the ground, and they're looking forward to the start of the season."
Essendon will take on Gold Coast at Metricon Stadium in their first NAB Challenge hit-out on February 17, before playing Port Adelaide at Etihad Stadium on February 25.
Twitter: @AFL_CalTwomey
